1 /*
2 * Copyright (c) 1997, 2018, 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_VM_RUNTIME_THREAD_HPP
26 #define SHARE_VM_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
71 class ciEnv;
72 class CompileThread;
73 class CompileLog;
74 class CompileTask;
75 class CompileQueue;
76 class CompilerCounters;
77 class vframeArray;
78
79 class DeoptResourceMark;
80 class jvmtiDeferredLocalVariableSet;
81
82 class GCTaskQueue;
83 class ThreadClosure;
84 class ICRefillVerifier;
85 class IdealGraphPrinter;
86
87 class Metadata;
88 template <class T, MEMFLAGS F> class ChunkedList;
89 typedef ChunkedList<Metadata*, mtInternal> MetadataOnStackBuffer;
90
91 DEBUG_ONLY(class ResourceMark;)
92
93 class WorkerThread;
94
95 // Class hierarchy
96 // - Thread
97 // - JavaThread
98 // - various subclasses eg CompilerThread, ServiceThread
99 // - NonJavaThread
100 // - NamedThread
101 // - VMThread
102 // - ConcurrentGCThread
103 // - WorkerThread
104 // - GangWorker
105 // - GCTaskThread
106 // - WatcherThread
107 // - JfrThreadSampler
108 //
109 // All Thread subclasses must be either JavaThread or NonJavaThread.
110 // This means !t->is_Java_thread() iff t is a NonJavaThread, or t is
111 // a partially constructed/destroyed Thread.
112
113 class Thread: public ThreadShadow {
114 friend class VMStructs;
115 friend class JVMCIVMStructs;
116 private:
117
118 #ifndef USE_LIBRARY_BASED_TLS_ONLY
119 // Current thread is maintained as a thread-local variable
120 static THREAD_LOCAL_DECL Thread* _thr_current;
121 #endif
122
123 private:
124 // Thread local data area available to the GC. The internal
125 // structure and contents of this data area is GC-specific.
126 // Only GC and GC barrier code should access this data area.
127 GCThreadLocalData _gc_data;
128
129 public:
130 static ByteSize gc_data_offset() {
131 return byte_offset_of(Thread, _gc_data);
132 }
133
134 template <typename T> T* gc_data() {
135 STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data));
136 return reinterpret_cast<T*>(&_gc_data);
137 }
138
139 // Exception handling
140 // (Note: _pending_exception and friends are in ThreadShadow)
141 //oop _pending_exception; // pending exception for current thread
142 // const char* _exception_file; // file information for exception (debugging only)
143 // int _exception_line; // line information for exception (debugging only)
144 protected:
145 // Support for forcing alignment of thread objects for biased locking
146 void* _real_malloc_address;
147
148 // JavaThread lifecycle support:
149 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
150 friend class ScanHazardPtrGatherProtectedThreadsClosure; // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
151 friend class ScanHazardPtrGatherThreadsListClosure; // for get_threads_hazard_ptr(), untag_hazard_ptr() access
152 friend class ScanHazardPtrPrintMatchingThreadsClosure; // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
153 friend class ThreadsSMRSupport; // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
154
155 ThreadsList* volatile _threads_hazard_ptr;
156 SafeThreadsListPtr* _threads_list_ptr;
157 ThreadsList* cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
158 ThreadsList* get_threads_hazard_ptr();
159 void set_threads_hazard_ptr(ThreadsList* new_list);
160 static bool is_hazard_ptr_tagged(ThreadsList* list) {
161 return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
162 }
163 static ThreadsList* tag_hazard_ptr(ThreadsList* list) {
164 return (ThreadsList*)(intptr_t(list) | intptr_t(1));
165 }
166 static ThreadsList* untag_hazard_ptr(ThreadsList* list) {
167 return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
168 }
169 // This field is enabled via -XX:+EnableThreadSMRStatistics:
170 uint _nested_threads_hazard_ptr_cnt;
171 void dec_nested_threads_hazard_ptr_cnt() {
172 assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
173 _nested_threads_hazard_ptr_cnt--;
174 }
175 void inc_nested_threads_hazard_ptr_cnt() {
176 _nested_threads_hazard_ptr_cnt++;
177 }
178 uint nested_threads_hazard_ptr_cnt() {
179 return _nested_threads_hazard_ptr_cnt;
180 }
181
182 public:
183 void* operator new(size_t size) throw() { return allocate(size, true); }
184 void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
185 return allocate(size, false); }
186 void operator delete(void* p);
187
188 protected:
189 static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
190 private:
191
192 // ***************************************************************
193 // Suspend and resume support
194 // ***************************************************************
195 //
196 // VM suspend/resume no longer exists - it was once used for various
197 // things including safepoints but was deprecated and finally removed
198 // in Java 7. Because VM suspension was considered "internal" Java-level
199 // suspension was considered "external", and this legacy naming scheme
200 // remains.
201 //
202 // External suspend/resume requests come from JVM_SuspendThread,
203 // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
204 // ResumeThread. External
205 // suspend requests cause _external_suspend to be set and external
206 // resume requests cause _external_suspend to be cleared.
207 // External suspend requests do not nest on top of other external
208 // suspend requests. The higher level APIs reject suspend requests
209 // for already suspended threads.
210 //
211 // The external_suspend
212 // flag is checked by has_special_runtime_exit_condition() and java thread
213 // will self-suspend when handle_special_runtime_exit_condition() is
214 // called. Most uses of the _thread_blocked state in JavaThreads are
215 // considered the same as being externally suspended; if the blocking
216 // condition lifts, the JavaThread will self-suspend. Other places
217 // where VM checks for external_suspend include:
218 // + mutex granting (do not enter monitors when thread is suspended)
219 // + state transitions from _thread_in_native
220 //
221 // In general, java_suspend() does not wait for an external suspend
222 // request to complete. When it returns, the only guarantee is that
223 // the _external_suspend field is true.
224 //
225 // wait_for_ext_suspend_completion() is used to wait for an external
226 // suspend request to complete. External suspend requests are usually
227 // followed by some other interface call that requires the thread to
228 // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
229 // the interface that requires quiescence, we give the JavaThread a
230 // chance to self-suspend before we need it to be quiescent. This
231 // improves overall suspend/query performance.
232 //
233 // _suspend_flags controls the behavior of java_ suspend/resume.
234 // It must be set under the protection of SR_lock. Read from the flag is
235 // OK without SR_lock as long as the value is only used as a hint.
236 // (e.g., check _external_suspend first without lock and then recheck
237 // inside SR_lock and finish the suspension)
238 //
239 // _suspend_flags is also overloaded for other "special conditions" so
240 // that a single check indicates whether any special action is needed
241 // eg. for async exceptions.
242 // -------------------------------------------------------------------
243 // Notes:
244 // 1. The suspend/resume logic no longer uses ThreadState in OSThread
245 // but we still update its value to keep other part of the system (mainly
246 // JVMTI) happy. ThreadState is legacy code (see notes in
247 // osThread.hpp).
248 //
249 // 2. It would be more natural if set_external_suspend() is private and
250 // part of java_suspend(), but that probably would affect the suspend/query
251 // performance. Need more investigation on this.
252
253 // suspend/resume lock: used for self-suspend
254 Monitor* _SR_lock;
255
256 protected:
257 enum SuspendFlags {
258 // NOTE: avoid using the sign-bit as cc generates different test code
259 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
260
261 _external_suspend = 0x20000000U, // thread is asked to self suspend
262 _ext_suspended = 0x40000000U, // thread has self-suspended
263 _deopt_suspend = 0x10000000U, // thread needs to self suspend for deopt
264
265 _has_async_exception = 0x00000001U, // there is a pending async exception
266 _critical_native_unlock = 0x00000002U, // Must call back to unlock JNI critical lock
267
268 _trace_flag = 0x00000004U // call tracing backend
269 };
270
271 // various suspension related flags - atomically updated
272 // overloaded for async exception checking in check_special_condition_for_native_trans.
273 volatile uint32_t _suspend_flags;
274
275 private:
276 int _num_nested_signal;
277
278 DEBUG_ONLY(bool _suspendible_thread;)
279
280 public:
281 void enter_signal_handler() { _num_nested_signal++; }
282 void leave_signal_handler() { _num_nested_signal--; }
283 bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
284
285 // Determines if a heap allocation failure will be retried
286 // (e.g., by deoptimizing and re-executing in the interpreter).
287 // In this case, the failed allocation must raise
288 // Universe::out_of_memory_error_retry() and omit side effects
289 // such as JVMTI events and handling -XX:+HeapDumpOnOutOfMemoryError
290 // and -XX:OnOutOfMemoryError.
291 virtual bool in_retryable_allocation() const { return false; }
292
293 #ifdef ASSERT
294 void set_suspendible_thread() {
295 _suspendible_thread = true;
296 }
297
298 void clear_suspendible_thread() {
299 _suspendible_thread = false;
300 }
301
302 bool is_suspendible_thread() { return _suspendible_thread; }
303 #endif
304
305 private:
306 // Active_handles points to a block of handles
307 JNIHandleBlock* _active_handles;
308
309 // One-element thread local free list
310 JNIHandleBlock* _free_handle_block;
311
312 // Point to the last handle mark
313 HandleMark* _last_handle_mark;
314
315 // The parity of the last strong_roots iteration in which this thread was
316 // claimed as a task.
317 int _oops_do_parity;
318
319 // Support for GlobalCounter
320 private:
321 volatile uintx _rcu_counter;
322 public:
323 volatile uintx* get_rcu_counter() {
324 return &_rcu_counter;
325 }
326
327 public:
328 void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; }
329 HandleMark* last_handle_mark() const { return _last_handle_mark; }
330 private:
331
332 #ifdef ASSERT
333 ICRefillVerifier* _missed_ic_stub_refill_verifier;
334
335 public:
336 ICRefillVerifier* missed_ic_stub_refill_verifier() {
337 return _missed_ic_stub_refill_verifier;
338 }
339
340 void set_missed_ic_stub_refill_verifier(ICRefillVerifier* verifier) {
341 _missed_ic_stub_refill_verifier = verifier;
342 }
343 #endif
344
345 private:
346
347 // debug support for checking if code does allow safepoints or not
348 // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on
349 // mutex, or blocking on an object synchronizer (Java locking).
350 // If !allow_safepoint(), then an assertion failure will happen in any of the above cases
351 // If !allow_allocation(), then an assertion failure will happen during allocation
352 // (Hence, !allow_safepoint() => !allow_allocation()).
353 //
354 // The two classes NoSafepointVerifier and No_Allocation_Verifier are used to set these counters.
355 //
356 NOT_PRODUCT(int _allow_safepoint_count;) // If 0, thread allow a safepoint to happen
357 debug_only(int _allow_allocation_count;) // If 0, the thread is allowed to allocate oops.
358
359 // Used by SkipGCALot class.
360 NOT_PRODUCT(bool _skip_gcalot;) // Should we elide gc-a-lot?
361
362 friend class NoAllocVerifier;
363 friend class NoSafepointVerifier;
364 friend class PauseNoSafepointVerifier;
365 friend class GCLocker;
366
367 volatile void* _polling_page; // Thread local polling page
368
369 ThreadLocalAllocBuffer _tlab; // Thread-local eden
370 jlong _allocated_bytes; // Cumulative number of bytes allocated on
371 // the Java heap
372 ThreadHeapSampler _heap_sampler; // For use when sampling the memory.
373
374 ThreadStatisticalInfo _statistical_info; // Statistics about the thread
375
376 JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;) // Thread-local data for jfr
377
378 int _vm_operation_started_count; // VM_Operation support
379 int _vm_operation_completed_count; // VM_Operation support
380
381 ObjectMonitor* _current_pending_monitor; // ObjectMonitor this thread
382 // is waiting to lock
383 bool _current_pending_monitor_is_from_java; // locking is from Java code
384
385 // ObjectMonitor on which this thread called Object.wait()
386 ObjectMonitor* _current_waiting_monitor;
387
388 // Private thread-local objectmonitor list - a simple cache organized as a SLL.
389 public:
390 ObjectMonitor* omFreeList;
391 int omFreeCount; // length of omFreeList
392 int omFreeProvision; // reload chunk size
393 ObjectMonitor* omInUseList; // SLL to track monitors in circulation
394 int omInUseCount; // length of omInUseList
395
396 #ifdef ASSERT
397 private:
398 bool _visited_for_critical_count;
399
400 public:
401 void set_visited_for_critical_count(bool z) { _visited_for_critical_count = z; }
402 bool was_visited_for_critical_count() const { return _visited_for_critical_count; }
403 #endif
404
405 public:
406 enum {
407 is_definitely_current_thread = true
408 };
409
410 // Constructor
411 Thread();
412 virtual ~Thread() = 0; // Thread is abstract.
413
414 // Manage Thread::current()
415 void initialize_thread_current();
416 static void clear_thread_current(); // TLS cleanup needed before threads terminate
417
418 protected:
419 // To be implemented by children.
420 virtual void run() = 0;
421
422 public:
423 // invokes <ChildThreadClass>::run(), with common preparations and cleanups.
424 void call_run();
425
426 // Testers
427 virtual bool is_VM_thread() const { return false; }
428 virtual bool is_Java_thread() const { return false; }
429 virtual bool is_Compiler_thread() const { return false; }
430 virtual bool is_Code_cache_sweeper_thread() const { return false; }
431 virtual bool is_hidden_from_external_view() const { return false; }
432 virtual bool is_jvmti_agent_thread() const { return false; }
433 // True iff the thread can perform GC operations at a safepoint.
434 // Generally will be true only of VM thread and parallel GC WorkGang
435 // threads.
436 virtual bool is_GC_task_thread() const { return false; }
437 virtual bool is_Watcher_thread() const { return false; }
438 virtual bool is_ConcurrentGC_thread() const { return false; }
439 virtual bool is_Named_thread() const { return false; }
440 virtual bool is_Worker_thread() const { return false; }
441
442 // Can this thread make Java upcalls
443 virtual bool can_call_java() const { return false; }
444
445 // Casts
446 virtual WorkerThread* as_Worker_thread() const { return NULL; }
447
448 virtual char* name() const { return (char*)"Unknown thread"; }
449
450 // Returns the current thread (ASSERTS if NULL)
451 static inline Thread* current();
452 // Returns the current thread, or NULL if not attached
453 static inline Thread* current_or_null();
454 // Returns the current thread, or NULL if not attached, and is
455 // safe for use from signal-handlers
456 static inline Thread* current_or_null_safe();
457
458 // Common thread operations
459 #ifdef ASSERT
460 static void check_for_dangling_thread_pointer(Thread *thread);
461 #endif
462 static void set_priority(Thread* thread, ThreadPriority priority);
463 static ThreadPriority get_priority(const Thread* const thread);
464 static void start(Thread* thread);
465 static void interrupt(Thread* thr);
466 static bool is_interrupted(Thread* thr, bool clear_interrupted);
467
468 void set_native_thread_name(const char *name) {
469 assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
470 os::set_native_thread_name(name);
471 }
472
473 ObjectMonitor** omInUseList_addr() { return (ObjectMonitor **)&omInUseList; }
474 Monitor* SR_lock() const { return _SR_lock; }
475
476 bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
477
478 inline void set_suspend_flag(SuspendFlags f);
479 inline void clear_suspend_flag(SuspendFlags f);
480
481 inline void set_has_async_exception();
482 inline void clear_has_async_exception();
483
484 bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
485
486 inline void set_critical_native_unlock();
487 inline void clear_critical_native_unlock();
488
489 inline void set_trace_flag();
490 inline void clear_trace_flag();
491
492 // Support for Unhandled Oop detection
493 // Add the field for both, fastdebug and debug, builds to keep
494 // Thread's fields layout the same.
495 // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
496 #ifdef CHECK_UNHANDLED_OOPS
497 private:
498 UnhandledOops* _unhandled_oops;
499 #elif defined(ASSERT)
500 private:
501 void* _unhandled_oops;
502 #endif
503 #ifdef CHECK_UNHANDLED_OOPS
504 public:
505 UnhandledOops* unhandled_oops() { return _unhandled_oops; }
506 // Mark oop safe for gc. It may be stack allocated but won't move.
507 void allow_unhandled_oop(oop *op) {
508 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
509 }
510 // Clear oops at safepoint so crashes point to unhandled oop violator
511 void clear_unhandled_oops() {
512 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
513 }
514 #endif // CHECK_UNHANDLED_OOPS
515
516 public:
517 #ifndef PRODUCT
518 bool skip_gcalot() { return _skip_gcalot; }
519 void set_skip_gcalot(bool v) { _skip_gcalot = v; }
520 #endif
521
522 // Installs a pending exception to be inserted later
523 static void send_async_exception(oop thread_oop, oop java_throwable);
524
525 // Resource area
526 ResourceArea* resource_area() const { return _resource_area; }
527 void set_resource_area(ResourceArea* area) { _resource_area = area; }
528
529 OSThread* osthread() const { return _osthread; }
530 void set_osthread(OSThread* thread) { _osthread = thread; }
531
532 // JNI handle support
533 JNIHandleBlock* active_handles() const { return _active_handles; }
534 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
535 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
536 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
537
538 // Internal handle support
539 HandleArea* handle_area() const { return _handle_area; }
540 void set_handle_area(HandleArea* area) { _handle_area = area; }
541
542 GrowableArray<Metadata*>* metadata_handles() const { return _metadata_handles; }
543 void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
544
545 // Thread-Local Allocation Buffer (TLAB) support
546 ThreadLocalAllocBuffer& tlab() { return _tlab; }
547 void initialize_tlab() {
548 if (UseTLAB) {
549 tlab().initialize();
550 }
551 }
552
553 jlong allocated_bytes() { return _allocated_bytes; }
554 void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
555 void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
556 inline jlong cooked_allocated_bytes();
557
558 ThreadHeapSampler& heap_sampler() { return _heap_sampler; }
559
560 ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
561
562 JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
563
564 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; }
565
566 // VM operation support
567 int vm_operation_ticket() { return ++_vm_operation_started_count; }
568 int vm_operation_completed_count() { return _vm_operation_completed_count; }
569 void increment_vm_operation_completed_count() { _vm_operation_completed_count++; }
570
571 // For tracking the heavyweight monitor the thread is pending on.
572 ObjectMonitor* current_pending_monitor() {
573 return _current_pending_monitor;
574 }
575 void set_current_pending_monitor(ObjectMonitor* monitor) {
576 _current_pending_monitor = monitor;
577 }
578 void set_current_pending_monitor_is_from_java(bool from_java) {
579 _current_pending_monitor_is_from_java = from_java;
580 }
581 bool current_pending_monitor_is_from_java() {
582 return _current_pending_monitor_is_from_java;
583 }
584
585 // For tracking the ObjectMonitor on which this thread called Object.wait()
586 ObjectMonitor* current_waiting_monitor() {
587 return _current_waiting_monitor;
588 }
589 void set_current_waiting_monitor(ObjectMonitor* monitor) {
590 _current_waiting_monitor = monitor;
591 }
592
593 // GC support
594 // Apply "f->do_oop" to all root oops in "this".
595 // Used by JavaThread::oops_do.
596 // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
597 virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
598
599 // Handles the parallel case for the method below.
600 private:
601 bool claim_oops_do_par_case(int collection_parity);
602 public:
603 // Requires that "collection_parity" is that of the current roots
604 // iteration. If "is_par" is false, sets the parity of "this" to
605 // "collection_parity", and returns "true". If "is_par" is true,
606 // uses an atomic instruction to set the current threads parity to
607 // "collection_parity", if it is not already. Returns "true" iff the
608 // calling thread does the update, this indicates that the calling thread
609 // has claimed the thread's stack as a root groop in the current
610 // collection.
611 bool claim_oops_do(bool is_par, int collection_parity) {
612 if (!is_par) {
613 _oops_do_parity = collection_parity;
614 return true;
615 } else {
616 return claim_oops_do_par_case(collection_parity);
617 }
618 }
619
620 // jvmtiRedefineClasses support
621 void metadata_handles_do(void f(Metadata*));
622
623 // Used by fast lock support
624 virtual bool is_lock_owned(address adr) const;
625
626 // Check if address is in the stack of the thread (not just for locks).
627 // Warning: the method can only be used on the running thread
628 bool is_in_stack(address adr) const;
629 // Check if address is in the usable part of the stack (excludes protected
630 // guard pages)
631 bool is_in_usable_stack(address adr) const;
632
633 // Sets this thread as starting thread. Returns failure if thread
634 // creation fails due to lack of memory, too many threads etc.
635 bool set_as_starting_thread();
636
637 protected:
638 // OS data associated with the thread
639 OSThread* _osthread; // Platform-specific thread information
640
641 // Thread local resource area for temporary allocation within the VM
642 ResourceArea* _resource_area;
643
644 DEBUG_ONLY(ResourceMark* _current_resource_mark;)
645
646 // Thread local handle area for allocation of handles within the VM
647 HandleArea* _handle_area;
648 GrowableArray<Metadata*>* _metadata_handles;
649
650 // Support for stack overflow handling, get_thread, etc.
651 address _stack_base;
652 size_t _stack_size;
653 uintptr_t _self_raw_id; // used by get_thread (mutable)
654 int _lgrp_id;
655
656 volatile void** polling_page_addr() { return &_polling_page; }
657
658 public:
659 // Stack overflow support
660 address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
661 void set_stack_base(address base) { _stack_base = base; }
662 size_t stack_size() const { return _stack_size; }
663 void set_stack_size(size_t size) { _stack_size = size; }
664 address stack_end() const { return stack_base() - stack_size(); }
665 void record_stack_base_and_size();
666 void register_thread_stack_with_NMT() NOT_NMT_RETURN;
667
668 bool on_local_stack(address adr) const {
669 // QQQ this has knowledge of direction, ought to be a stack method
670 return (_stack_base >= adr && adr >= stack_end());
671 }
672
673 uintptr_t self_raw_id() { return _self_raw_id; }
674 void set_self_raw_id(uintptr_t value) { _self_raw_id = value; }
675
676 int lgrp_id() const { return _lgrp_id; }
677 void set_lgrp_id(int value) { _lgrp_id = value; }
678
679 // Printing
680 void print_on(outputStream* st, bool print_extended_info) const;
681 virtual void print_on(outputStream* st) const { print_on(st, false); }
682 void print() const { print_on(tty); }
683 virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
684 void print_value_on(outputStream* st) const;
685
686 // Debug-only code
687 #ifdef ASSERT
688 private:
689 // Deadlock detection support for Mutex locks. List of locks own by thread.
690 Monitor* _owned_locks;
691 // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
692 // thus the friendship
693 friend class Mutex;
694 friend class Monitor;
695
696 public:
697 void print_owned_locks_on(outputStream* st) const;
698 void print_owned_locks() const { print_owned_locks_on(tty); }
699 Monitor* owned_locks() const { return _owned_locks; }
700 bool owns_locks() const { return owned_locks() != NULL; }
701 bool owns_locks_but_compiled_lock() const;
702 int oops_do_parity() const { return _oops_do_parity; }
703
704 // Deadlock detection
705 bool allow_allocation() { return _allow_allocation_count == 0; }
706 ResourceMark* current_resource_mark() { return _current_resource_mark; }
707 void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
708 #endif
709
710 void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN;
711
712 private:
713 volatile int _jvmti_env_iteration_count;
714
715 public:
716 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; }
717 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; }
718 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; }
719
720 // Code generation
721 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file); }
722 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line); }
723 static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles); }
724
725 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base); }
726 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size); }
727
728 static ByteSize polling_page_offset() { return byte_offset_of(Thread, _polling_page); }
729
730 static ByteSize tlab_start_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); }
731 static ByteSize tlab_end_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); }
732 static ByteSize tlab_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); }
733 static ByteSize tlab_pf_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); }
734
735 static ByteSize allocated_bytes_offset() { return byte_offset_of(Thread, _allocated_bytes); }
736
737 JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
738
739 public:
740 volatile intptr_t _Stalled;
741 volatile int _TypeTag;
742 ParkEvent * _ParkEvent; // for synchronized()
743 ParkEvent * _SleepEvent; // for Thread.sleep
744 ParkEvent * _MutexEvent; // for native internal Mutex/Monitor
745 ParkEvent * _MuxEvent; // for low-level muxAcquire-muxRelease
746 int NativeSyncRecursion; // diagnostic
747
748 volatile int _OnTrap; // Resume-at IP delta
749 jint _hashStateW; // Marsaglia Shift-XOR thread-local RNG
750 jint _hashStateX; // thread-specific hashCode generator state
751 jint _hashStateY;
752 jint _hashStateZ;
753
754 volatile jint rng[4]; // RNG for spin loop
755
756 // Low-level leaf-lock primitives used to implement synchronization
757 // and native monitor-mutex infrastructure.
758 // Not for general synchronization use.
759 static void SpinAcquire(volatile int * Lock, const char * Name);
760 static void SpinRelease(volatile int * Lock);
761 static void muxAcquire(volatile intptr_t * Lock, const char * Name);
762 static void muxAcquireW(volatile intptr_t * Lock, ParkEvent * ev);
763 static void muxRelease(volatile intptr_t * Lock);
764 };
765
766 // Inline implementation of Thread::current()
767 inline Thread* Thread::current() {
768 Thread* current = current_or_null();
769 assert(current != NULL, "Thread::current() called on detached thread");
770 return current;
771 }
772
773 inline Thread* Thread::current_or_null() {
774 #ifndef USE_LIBRARY_BASED_TLS_ONLY
775 return _thr_current;
776 #else
777 if (ThreadLocalStorage::is_initialized()) {
778 return ThreadLocalStorage::thread();
779 }
780 return NULL;
781 #endif
782 }
783
784 inline Thread* Thread::current_or_null_safe() {
785 if (ThreadLocalStorage::is_initialized()) {
786 return ThreadLocalStorage::thread();
787 }
788 return NULL;
789 }
790
791 class NonJavaThread: public Thread {
792 friend class VMStructs;
793
794 NonJavaThread* volatile _next;
795
796 class List;
797 static List _the_list;
798
799 public:
800 NonJavaThread();
801 ~NonJavaThread();
802
803 class Iterator;
804 };
805
806 // Provides iteration over the list of NonJavaThreads. Because list
807 // management occurs in the NonJavaThread constructor and destructor,
808 // entries in the list may not be fully constructed instances of a
809 // derived class. Threads created after an iterator is constructed
810 // will not be visited by the iterator. The scope of an iterator is a
811 // critical section; there must be no safepoint checks in that scope.
812 class NonJavaThread::Iterator : public StackObj {
813 uint _protect_enter;
814 NonJavaThread* _current;
815
816 // Noncopyable.
817 Iterator(const Iterator&);
818 Iterator& operator=(const Iterator&);
819
820 public:
821 Iterator();
822 ~Iterator();
823
824 bool end() const { return _current == NULL; }
825 NonJavaThread* current() const { return _current; }
826 void step();
827 };
828
829 // Name support for threads. non-JavaThread subclasses with multiple
830 // uniquely named instances should derive from this.
831 class NamedThread: public NonJavaThread {
832 friend class VMStructs;
833 enum {
834 max_name_len = 64
835 };
836 private:
837 char* _name;
838 // log JavaThread being processed by oops_do
839 JavaThread* _processed_thread;
840 uint _gc_id; // The current GC id when a thread takes part in GC
841
842 public:
843 NamedThread();
844 ~NamedThread();
845 // May only be called once per thread.
846 void set_name(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
847 void initialize_named_thread();
848 virtual bool is_Named_thread() const { return true; }
849 virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
850 JavaThread *processed_thread() { return _processed_thread; }
851 void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
852 virtual void print_on(outputStream* st) const;
853
854 void set_gc_id(uint gc_id) { _gc_id = gc_id; }
855 uint gc_id() { return _gc_id; }
856 };
857
858 // Worker threads are named and have an id of an assigned work.
859 class WorkerThread: public NamedThread {
860 private:
861 uint _id;
862 public:
863 WorkerThread() : _id(0) { }
864 virtual bool is_Worker_thread() const { return true; }
865
866 virtual WorkerThread* as_Worker_thread() const {
867 assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
868 return (WorkerThread*) this;
869 }
870
871 void set_id(uint work_id) { _id = work_id; }
872 uint id() const { return _id; }
873 };
874
875 // A single WatcherThread is used for simulating timer interrupts.
876 class WatcherThread: public NonJavaThread {
877 friend class VMStructs;
878 public:
879 virtual void run();
880
881 private:
882 static WatcherThread* _watcher_thread;
883
884 static bool _startable;
885 // volatile due to at least one lock-free read
886 volatile static bool _should_terminate;
887 public:
888 enum SomeConstants {
889 delay_interval = 10 // interrupt delay in milliseconds
890 };
891
892 // Constructor
893 WatcherThread();
894
895 // No destruction allowed
896 ~WatcherThread() {
897 guarantee(false, "WatcherThread deletion must fix the race with VM termination");
898 }
899
900 // Tester
901 bool is_Watcher_thread() const { return true; }
902
903 // Printing
904 char* name() const { return (char*)"VM Periodic Task Thread"; }
905 void print_on(outputStream* st) const;
906 void unpark();
907
908 // Returns the single instance of WatcherThread
909 static WatcherThread* watcher_thread() { return _watcher_thread; }
910
911 // Create and start the single instance of WatcherThread, or stop it on shutdown
912 static void start();
913 static void stop();
914 // Only allow start once the VM is sufficiently initialized
915 // Otherwise the first task to enroll will trigger the start
916 static void make_startable();
917 private:
918 int sleep() const;
919 };
920
921
922 class CompilerThread;
923
924 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
925
926 class JavaThread: public Thread {
927 friend class VMStructs;
928 friend class JVMCIVMStructs;
929 friend class WhiteBox;
930 private:
931 JavaThread* _next; // The next thread in the Threads list
932 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
933 oop _threadObj; // The Java level thread object
934
935 #ifdef ASSERT
936 private:
937 int _java_call_counter;
938
939 public:
940 int java_call_counter() { return _java_call_counter; }
941 void inc_java_call_counter() { _java_call_counter++; }
942 void dec_java_call_counter() {
943 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
944 _java_call_counter--;
945 }
946 private: // restore original namespace restriction
947 #endif // ifdef ASSERT
948
949 #ifndef PRODUCT
950 public:
951 enum {
952 jump_ring_buffer_size = 16
953 };
954 private: // restore original namespace restriction
955 #endif
956
957 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
958
959 ThreadFunction _entry_point;
960
961 JNIEnv _jni_environment;
962
963 // Deopt support
964 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
965
966 intptr_t* _must_deopt_id; // id of frame that needs to be deopted once we
967 // transition out of native
968 CompiledMethod* _deopt_nmethod; // CompiledMethod that is currently being deoptimized
969 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
970 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
971 // Because deoptimization is lazy we must save jvmti requests to set locals
972 // in compiled frames until we deoptimize and we have an interpreter frame.
973 // This holds the pointer to array (yeah like there might be more than one) of
974 // description of compiled vframes that have locals that need to be updated.
975 GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
976
977 // Handshake value for fixing 6243940. We need a place for the i2c
978 // adapter to store the callee Method*. This value is NEVER live
979 // across a gc point so it does NOT have to be gc'd
980 // The handshake is open ended since we can't be certain that it will
981 // be NULLed. This is because we rarely ever see the race and end up
982 // in handle_wrong_method which is the backend of the handshake. See
983 // code in i2c adapters and handle_wrong_method.
984
985 Method* _callee_target;
986
987 // Used to pass back results to the interpreter or generated code running Java code.
988 oop _vm_result; // oop result is GC-preserved
989 Metadata* _vm_result_2; // non-oop result
990
991 // See ReduceInitialCardMarks: this holds the precise space interval of
992 // the most recent slow path allocation for which compiled code has
993 // elided card-marks for performance along the fast-path.
994 MemRegion _deferred_card_mark;
995
996 MonitorChunk* _monitor_chunks; // Contains the off stack monitors
997 // allocated during deoptimization
998 // and by JNI_MonitorEnter/Exit
999
1000 // Async. requests support
1001 enum AsyncRequests {
1002 _no_async_condition = 0,
1003 _async_exception,
1004 _async_unsafe_access_error
1005 };
1006 AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
1007 oop _pending_async_exception;
1008
1009 // Safepoint support
1010 public: // Expose _thread_state for SafeFetchInt()
1011 volatile JavaThreadState _thread_state;
1012 private:
1013 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint
1014 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
1015
1016 // JavaThread termination support
1017 enum TerminatedTypes {
1018 _not_terminated = 0xDEAD - 2,
1019 _thread_exiting, // JavaThread::exit() has been called for this thread
1020 _thread_terminated, // JavaThread is removed from thread list
1021 _vm_exited // JavaThread is still executing native code, but VM is terminated
1022 // only VM_Exit can set _vm_exited
1023 };
1024
1025 // In general a JavaThread's _terminated field transitions as follows:
1026 //
1027 // _not_terminated => _thread_exiting => _thread_terminated
1028 //
1029 // _vm_exited is a special value to cover the case of a JavaThread
1030 // executing native code after the VM itself is terminated.
1031 volatile TerminatedTypes _terminated;
1032 // suspend/resume support
1033 volatile bool _suspend_equivalent; // Suspend equivalent condition
1034 jint _in_deopt_handler; // count of deoptimization
1035 // handlers thread is in
1036 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
1037 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
1038 // never locked) when throwing an exception. Used by interpreter only.
1039
1040 // JNI attach states:
1041 enum JNIAttachStates {
1042 _not_attaching_via_jni = 1, // thread is not attaching via JNI
1043 _attaching_via_jni, // thread is attaching via JNI
1044 _attached_via_jni // thread has attached via JNI
1045 };
1046
1047 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
1048 // A native thread that is attaching via JNI starts with a value
1049 // of _attaching_via_jni and transitions to _attached_via_jni.
1050 volatile JNIAttachStates _jni_attach_state;
1051
1052 public:
1053 // State of the stack guard pages for this thread.
1054 enum StackGuardState {
1055 stack_guard_unused, // not needed
1056 stack_guard_reserved_disabled,
1057 stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
1058 stack_guard_enabled // enabled
1059 };
1060
1061 private:
1062
1063 #if INCLUDE_JVMCI
1064 // The _pending_* fields below are used to communicate extra information
1065 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
1066
1067 // Communicates the DeoptReason and DeoptAction of the uncommon trap
1068 int _pending_deoptimization;
1069
1070 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
1071 // before the monitor has been acquired.
1072 bool _pending_monitorenter;
1073
1074 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
1075 bool _pending_transfer_to_interpreter;
1076
1077 // Guard for re-entrant call to JVMCIRuntime::adjust_comp_level
1078 bool _adjusting_comp_level;
1079
1080 // True if in a runtime call from compiled code that will deoptimize
1081 // and re-execute a failed heap allocation in the interpreter.
1082 bool _in_retryable_allocation;
1083
1084 // An id of a speculation that JVMCI compiled code can use to further describe and
1085 // uniquely identify the speculative optimization guarded by the uncommon trap
1086 long _pending_failed_speculation;
1087
1088 // These fields are mutually exclusive in terms of live ranges.
1089 union {
1090 // Communicates the pc at which the most recent implicit exception occurred
1091 // from the signal handler to a deoptimization stub.
1092 address _implicit_exception_pc;
1093
1094 // Communicates an alternative call target to an i2c stub from a JavaCall .
1095 address _alternate_call_target;
1096 } _jvmci;
1097
1098 // Support for high precision, thread sensitive counters in JVMCI compiled code.
1099 jlong* _jvmci_counters;
1100
1101 public:
1102 static jlong* _jvmci_old_thread_counters;
1103 static void collect_counters(typeArrayOop array);
1104 private:
1105 #endif // INCLUDE_JVMCI
1106
1107 StackGuardState _stack_guard_state;
1108
1109 // Precompute the limit of the stack as used in stack overflow checks.
1110 // We load it from here to simplify the stack overflow check in assembly.
1111 address _stack_overflow_limit;
1112 address _reserved_stack_activation;
1113
1114 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1115 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1116 // code)
1117 volatile oop _exception_oop; // Exception thrown in compiled code
1118 volatile address _exception_pc; // PC where exception happened
1119 volatile address _exception_handler_pc; // PC for handler of exception
1120 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
1121
1122 private:
1123 // support for JNI critical regions
1124 jint _jni_active_critical; // count of entries into JNI critical region
1125
1126 // Checked JNI: function name requires exception check
1127 char* _pending_jni_exception_check_fn;
1128
1129 // For deadlock detection.
1130 int _depth_first_number;
1131
1132 // JVMTI PopFrame support
1133 // This is set to popframe_pending to signal that top Java frame should be popped immediately
1134 int _popframe_condition;
1135
1136 // If reallocation of scalar replaced objects fails, we throw OOM
1137 // and during exception propagation, pop the top
1138 // _frames_to_pop_failed_realloc frames, the ones that reference
1139 // failed reallocations.
1140 int _frames_to_pop_failed_realloc;
1141
1142 #ifndef PRODUCT
1143 int _jmp_ring_index;
1144 struct {
1145 // We use intptr_t instead of address so debugger doesn't try and display strings
1146 intptr_t _target;
1147 intptr_t _instruction;
1148 const char* _file;
1149 int _line;
1150 } _jmp_ring[jump_ring_buffer_size];
1151 #endif // PRODUCT
1152
1153 friend class VMThread;
1154 friend class ThreadWaitTransition;
1155 friend class VM_Exit;
1156
1157 void initialize(); // Initialized the instance variables
1158
1159 public:
1160 // Constructor
1161 JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1162 JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1163 ~JavaThread();
1164
1165 #ifdef ASSERT
1166 // verify this JavaThread hasn't be published in the Threads::list yet
1167 void verify_not_published();
1168 #endif
1169
1170 //JNI functiontable getter/setter for JVMTI jni function table interception API.
1171 void set_jni_functions(struct JNINativeInterface_* functionTable) {
1172 _jni_environment.functions = functionTable;
1173 }
1174 struct JNINativeInterface_* get_jni_functions() {
1175 return (struct JNINativeInterface_ *)_jni_environment.functions;
1176 }
1177
1178 // This function is called at thread creation to allow
1179 // platform specific thread variables to be initialized.
1180 void cache_global_variables();
1181
1182 // Executes Shutdown.shutdown()
1183 void invoke_shutdown_hooks();
1184
1185 // Cleanup on thread exit
1186 enum ExitType {
1187 normal_exit,
1188 jni_detach
1189 };
1190 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1191
1192 void cleanup_failed_attach_current_thread();
1193
1194 // Testers
1195 virtual bool is_Java_thread() const { return true; }
1196 virtual bool can_call_java() const { return true; }
1197
1198 // Thread chain operations
1199 JavaThread* next() const { return _next; }
1200 void set_next(JavaThread* p) { _next = p; }
1201
1202 // Thread oop. threadObj() can be NULL for initial JavaThread
1203 // (or for threads attached via JNI)
1204 oop threadObj() const { return _threadObj; }
1205 void set_threadObj(oop p) { _threadObj = p; }
1206
1207 ThreadPriority java_priority() const; // Read from threadObj()
1208
1209 // Prepare thread and add to priority queue. If a priority is
1210 // not specified, use the priority of the thread object. Threads_lock
1211 // must be held while this function is called.
1212 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1213
1214 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
1215 address saved_exception_pc() { return _saved_exception_pc; }
1216
1217
1218 ThreadFunction entry_point() const { return _entry_point; }
1219
1220 // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1221 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1222
1223 // Last frame anchor routines
1224
1225 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
1226
1227 // last_Java_sp
1228 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
1229 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
1230
1231 // last_Java_pc
1232
1233 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
1234
1235 // Safepoint support
1236 #if !(defined(PPC64) || defined(AARCH64))
1237 JavaThreadState thread_state() const { return _thread_state; }
1238 void set_thread_state(JavaThreadState s) { _thread_state = s; }
1239 #else
1240 // Use membars when accessing volatile _thread_state. See
1241 // Threads::create_vm() for size checks.
1242 inline JavaThreadState thread_state() const;
1243 inline void set_thread_state(JavaThreadState s);
1244 #endif
1245 inline ThreadSafepointState* safepoint_state() const;
1246 inline void set_safepoint_state(ThreadSafepointState* state);
1247 inline bool is_at_poll_safepoint();
1248
1249 // JavaThread termination and lifecycle support:
1250 void smr_delete();
1251 bool on_thread_list() const { return _on_thread_list; }
1252 void set_on_thread_list() { _on_thread_list = true; }
1253
1254 // thread has called JavaThread::exit() or is terminated
1255 bool is_exiting() const;
1256 // thread is terminated (no longer on the threads list); we compare
1257 // against the two non-terminated values so that a freed JavaThread
1258 // will also be considered terminated.
1259 bool check_is_terminated(TerminatedTypes l_terminated) const {
1260 return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1261 }
1262 bool is_terminated() const;
1263 void set_terminated(TerminatedTypes t);
1264 // special for Threads::remove() which is static:
1265 void set_terminated_value();
1266 void block_if_vm_exited();
1267
1268 bool doing_unsafe_access() { return _doing_unsafe_access; }
1269 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
1270
1271 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
1272 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1273
1274 inline void set_polling_page_release(void* poll_value);
1275 inline void set_polling_page(void* poll_value);
1276 inline volatile void* get_polling_page();
1277
1278 private:
1279 // Support for thread handshake operations
1280 HandshakeState _handshake;
1281 public:
1282 void set_handshake_operation(HandshakeOperation* op) {
1283 _handshake.set_operation(this, op);
1284 }
1285
1286 bool has_handshake() const {
1287 return _handshake.has_operation();
1288 }
1289
1290 void handshake_process_by_self() {
1291 _handshake.process_by_self(this);
1292 }
1293
1294 void handshake_process_by_vmthread() {
1295 _handshake.process_by_vmthread(this);
1296 }
1297
1298 // Suspend/resume support for JavaThread
1299 private:
1300 inline void set_ext_suspended();
1301 inline void clear_ext_suspended();
1302
1303 public:
1304 void java_suspend();
1305 void java_resume();
1306 int java_suspend_self();
1307
1308 void check_and_wait_while_suspended() {
1309 assert(JavaThread::current() == this, "sanity check");
1310
1311 bool do_self_suspend;
1312 do {
1313 // were we externally suspended while we were waiting?
1314 do_self_suspend = handle_special_suspend_equivalent_condition();
1315 if (do_self_suspend) {
1316 // don't surprise the thread that suspended us by returning
1317 java_suspend_self();
1318 set_suspend_equivalent();
1319 }
1320 } while (do_self_suspend);
1321 }
1322 static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1323 // Check for async exception in addition to safepoint and suspend request.
1324 static void check_special_condition_for_native_trans(JavaThread *thread);
1325
1326 // Same as check_special_condition_for_native_trans but finishes the
1327 // transition into thread_in_Java mode so that it can potentially
1328 // block.
1329 static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1330
1331 bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1332 bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1333 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1334 // Warning: is_ext_suspend_completed() may temporarily drop the
1335 // SR_lock to allow the thread to reach a stable thread state if
1336 // it is currently in a transient thread state.
1337 return is_ext_suspend_completed(false /* !called_by_wait */,
1338 SuspendRetryDelay, bits);
1339 }
1340
1341 // We cannot allow wait_for_ext_suspend_completion() to run forever or
1342 // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1343 // passed as the count and delay parameters. Experiments with specific
1344 // calls to wait_for_ext_suspend_completion() can be done by passing
1345 // other values in the code. Experiments with all calls can be done
1346 // via the appropriate -XX options.
1347 bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1348
1349 // test for suspend - most (all?) of these should go away
1350 bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits);
1351
1352 inline void set_external_suspend();
1353 inline void clear_external_suspend();
1354
1355 inline void set_deopt_suspend();
1356 inline void clear_deopt_suspend();
1357 bool is_deopt_suspend() { return (_suspend_flags & _deopt_suspend) != 0; }
1358
1359 bool is_external_suspend() const {
1360 return (_suspend_flags & _external_suspend) != 0;
1361 }
1362 // Whenever a thread transitions from native to vm/java it must suspend
1363 // if external|deopt suspend is present.
1364 bool is_suspend_after_native() const {
1365 return (_suspend_flags & (_external_suspend | _deopt_suspend)) != 0;
1366 }
1367
1368 // external suspend request is completed
1369 bool is_ext_suspended() const {
1370 return (_suspend_flags & _ext_suspended) != 0;
1371 }
1372
1373 bool is_external_suspend_with_lock() const {
1374 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1375 return is_external_suspend();
1376 }
1377
1378 // Special method to handle a pending external suspend request
1379 // when a suspend equivalent condition lifts.
1380 bool handle_special_suspend_equivalent_condition() {
1381 assert(is_suspend_equivalent(),
1382 "should only be called in a suspend equivalence condition");
1383 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1384 bool ret = is_external_suspend();
1385 if (!ret) {
1386 // not about to self-suspend so clear suspend equivalence
1387 clear_suspend_equivalent();
1388 }
1389 // implied else:
1390 // We have a pending external suspend request so we leave the
1391 // suspend_equivalent flag set until java_suspend_self() sets
1392 // the ext_suspended flag and clears the suspend_equivalent
1393 // flag. This insures that wait_for_ext_suspend_completion()
1394 // will return consistent values.
1395 return ret;
1396 }
1397
1398 // utility methods to see if we are doing some kind of suspension
1399 bool is_being_ext_suspended() const {
1400 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1401 return is_ext_suspended() || is_external_suspend();
1402 }
1403
1404 bool is_suspend_equivalent() const { return _suspend_equivalent; }
1405
1406 void set_suspend_equivalent() { _suspend_equivalent = true; }
1407 void clear_suspend_equivalent() { _suspend_equivalent = false; }
1408
1409 // Thread.stop support
1410 void send_thread_stop(oop throwable);
1411 AsyncRequests clear_special_runtime_exit_condition() {
1412 AsyncRequests x = _special_runtime_exit_condition;
1413 _special_runtime_exit_condition = _no_async_condition;
1414 return x;
1415 }
1416
1417 // Are any async conditions present?
1418 bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1419
1420 void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1421
1422 // these next two are also used for self-suspension and async exception support
1423 void handle_special_runtime_exit_condition(bool check_asyncs = true);
1424
1425 // Return true if JavaThread has an asynchronous condition or
1426 // if external suspension is requested.
1427 bool has_special_runtime_exit_condition() {
1428 // Because we don't use is_external_suspend_with_lock
1429 // it is possible that we won't see an asynchronous external suspend
1430 // request that has just gotten started, i.e., SR_lock grabbed but
1431 // _external_suspend field change either not made yet or not visible
1432 // yet. However, this is okay because the request is asynchronous and
1433 // we will see the new flag value the next time through. It's also
1434 // possible that the external suspend request is dropped after
1435 // we have checked is_external_suspend(), we will recheck its value
1436 // under SR_lock in java_suspend_self().
1437 return (_special_runtime_exit_condition != _no_async_condition) ||
1438 is_external_suspend() || is_trace_suspend();
1439 }
1440
1441 void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; }
1442
1443 inline void set_pending_async_exception(oop e);
1444
1445 // Fast-locking support
1446 bool is_lock_owned(address adr) const;
1447
1448 // Accessors for vframe array top
1449 // The linked list of vframe arrays are sorted on sp. This means when we
1450 // unpack the head must contain the vframe array to unpack.
1451 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1452 vframeArray* vframe_array_head() const { return _vframe_array_head; }
1453
1454 // Side structure for deferring update of java frame locals until deopt occurs
1455 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1456 void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1457
1458 // These only really exist to make debugging deopt problems simpler
1459
1460 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1461 vframeArray* vframe_array_last() const { return _vframe_array_last; }
1462
1463 // The special resourceMark used during deoptimization
1464
1465 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
1466 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
1467
1468 intptr_t* must_deopt_id() { return _must_deopt_id; }
1469 void set_must_deopt_id(intptr_t* id) { _must_deopt_id = id; }
1470 void clear_must_deopt_id() { _must_deopt_id = NULL; }
1471
1472 void set_deopt_compiled_method(CompiledMethod* nm) { _deopt_nmethod = nm; }
1473 CompiledMethod* deopt_compiled_method() { return _deopt_nmethod; }
1474
1475 Method* callee_target() const { return _callee_target; }
1476 void set_callee_target (Method* x) { _callee_target = x; }
1477
1478 // Oop results of vm runtime calls
1479 oop vm_result() const { return _vm_result; }
1480 void set_vm_result (oop x) { _vm_result = x; }
1481
1482 Metadata* vm_result_2() const { return _vm_result_2; }
1483 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
1484
1485 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
1486 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
1487
1488 #if INCLUDE_JVMCI
1489 int pending_deoptimization() const { return _pending_deoptimization; }
1490 long pending_failed_speculation() const { return _pending_failed_speculation; }
1491 bool adjusting_comp_level() const { return _adjusting_comp_level; }
1492 void set_adjusting_comp_level(bool b) { _adjusting_comp_level = b; }
1493 bool has_pending_monitorenter() const { return _pending_monitorenter; }
1494 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
1495 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
1496 void set_pending_failed_speculation(long failed_speculation) { _pending_failed_speculation = failed_speculation; }
1497 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1498 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1499 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1500
1501 virtual bool in_retryable_allocation() const { return _in_retryable_allocation; }
1502 void set_in_retryable_allocation(bool b) { _in_retryable_allocation = b; }
1503 #endif // INCLUDE_JVMCI
1504
1505 // Exception handling for compiled methods
1506 oop exception_oop() const { return _exception_oop; }
1507 address exception_pc() const { return _exception_pc; }
1508 address exception_handler_pc() const { return _exception_handler_pc; }
1509 bool is_method_handle_return() const { return _is_method_handle_return == 1; }
1510
1511 void set_exception_oop(oop o) { (void)const_cast<oop&>(_exception_oop = o); }
1512 void set_exception_pc(address a) { _exception_pc = a; }
1513 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
1514 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
1515
1516 void clear_exception_oop_and_pc() {
1517 set_exception_oop(NULL);
1518 set_exception_pc(NULL);
1519 }
1520
1521 // Stack overflow support
1522 //
1523 // (small addresses)
1524 //
1525 // -- <-- stack_end() ---
1526 // | |
1527 // | red pages |
1528 // | |
1529 // -- <-- stack_red_zone_base() |
1530 // | |
1531 // | guard
1532 // | yellow pages zone
1533 // | |
1534 // | |
1535 // -- <-- stack_yellow_zone_base() |
1536 // | |
1537 // | |
1538 // | reserved pages |
1539 // | |
1540 // -- <-- stack_reserved_zone_base() --- ---
1541 // /|\ shadow <-- stack_overflow_limit() (somewhere in here)
1542 // | zone
1543 // \|/ size
1544 // some untouched memory ---
1545 //
1546 //
1547 // --
1548 // |
1549 // | shadow zone
1550 // |
1551 // --
1552 // x frame n
1553 // --
1554 // x frame n-1
1555 // x
1556 // --
1557 // ...
1558 //
1559 // --
1560 // x frame 0
1561 // -- <-- stack_base()
1562 //
1563 // (large addresses)
1564 //
1565
1566 private:
1567 // These values are derived from flags StackRedPages, StackYellowPages,
1568 // StackReservedPages and StackShadowPages. The zone size is determined
1569 // ergonomically if page_size > 4K.
1570 static size_t _stack_red_zone_size;
1571 static size_t _stack_yellow_zone_size;
1572 static size_t _stack_reserved_zone_size;
1573 static size_t _stack_shadow_zone_size;
1574 public:
1575 inline size_t stack_available(address cur_sp);
1576
1577 static size_t stack_red_zone_size() {
1578 assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1579 return _stack_red_zone_size;
1580 }
1581 static void set_stack_red_zone_size(size_t s) {
1582 assert(is_aligned(s, os::vm_page_size()),
1583 "We can not protect if the red zone size is not page aligned.");
1584 assert(_stack_red_zone_size == 0, "This should be called only once.");
1585 _stack_red_zone_size = s;
1586 }
1587 address stack_red_zone_base() {
1588 return (address)(stack_end() + stack_red_zone_size());
1589 }
1590 bool in_stack_red_zone(address a) {
1591 return a <= stack_red_zone_base() && a >= stack_end();
1592 }
1593
1594 static size_t stack_yellow_zone_size() {
1595 assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1596 return _stack_yellow_zone_size;
1597 }
1598 static void set_stack_yellow_zone_size(size_t s) {
1599 assert(is_aligned(s, os::vm_page_size()),
1600 "We can not protect if the yellow zone size is not page aligned.");
1601 assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1602 _stack_yellow_zone_size = s;
1603 }
1604
1605 static size_t stack_reserved_zone_size() {
1606 // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1607 return _stack_reserved_zone_size;
1608 }
1609 static void set_stack_reserved_zone_size(size_t s) {
1610 assert(is_aligned(s, os::vm_page_size()),
1611 "We can not protect if the reserved zone size is not page aligned.");
1612 assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1613 _stack_reserved_zone_size = s;
1614 }
1615 address stack_reserved_zone_base() {
1616 return (address)(stack_end() +
1617 (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1618 }
1619 bool in_stack_reserved_zone(address a) {
1620 return (a <= stack_reserved_zone_base()) &&
1621 (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1622 }
1623
1624 static size_t stack_yellow_reserved_zone_size() {
1625 return _stack_yellow_zone_size + _stack_reserved_zone_size;
1626 }
1627 bool in_stack_yellow_reserved_zone(address a) {
1628 return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1629 }
1630
1631 // Size of red + yellow + reserved zones.
1632 static size_t stack_guard_zone_size() {
1633 return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1634 }
1635
1636 static size_t stack_shadow_zone_size() {
1637 assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1638 return _stack_shadow_zone_size;
1639 }
1640 static void set_stack_shadow_zone_size(size_t s) {
1641 // The shadow area is not allocated or protected, so
1642 // it needs not be page aligned.
1643 // But the stack bang currently assumes that it is a
1644 // multiple of page size. This guarantees that the bang
1645 // loop touches all pages in the shadow zone.
1646 // This can be guaranteed differently, as well. E.g., if
1647 // the page size is a multiple of 4K, banging in 4K steps
1648 // suffices to touch all pages. (Some pages are banged
1649 // several times, though.)
1650 assert(is_aligned(s, os::vm_page_size()),
1651 "Stack bang assumes multiple of page size.");
1652 assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1653 _stack_shadow_zone_size = s;
1654 }
1655
1656 void create_stack_guard_pages();
1657 void remove_stack_guard_pages();
1658
1659 void enable_stack_reserved_zone();
1660 void disable_stack_reserved_zone();
1661 void enable_stack_yellow_reserved_zone();
1662 void disable_stack_yellow_reserved_zone();
1663 void enable_stack_red_zone();
1664 void disable_stack_red_zone();
1665
1666 inline bool stack_guard_zone_unused();
1667 inline bool stack_yellow_reserved_zone_disabled();
1668 inline bool stack_reserved_zone_disabled();
1669 inline bool stack_guards_enabled();
1670
1671 address reserved_stack_activation() const { return _reserved_stack_activation; }
1672 void set_reserved_stack_activation(address addr) {
1673 assert(_reserved_stack_activation == stack_base()
1674 || _reserved_stack_activation == NULL
1675 || addr == stack_base(), "Must not be set twice");
1676 _reserved_stack_activation = addr;
1677 }
1678
1679 // Attempt to reguard the stack after a stack overflow may have occurred.
1680 // Returns true if (a) guard pages are not needed on this thread, (b) the
1681 // pages are already guarded, or (c) the pages were successfully reguarded.
1682 // Returns false if there is not enough stack space to reguard the pages, in
1683 // which case the caller should unwind a frame and try again. The argument
1684 // should be the caller's (approximate) sp.
1685 bool reguard_stack(address cur_sp);
1686 // Similar to above but see if current stackpoint is out of the guard area
1687 // and reguard if possible.
1688 bool reguard_stack(void);
1689
1690 address stack_overflow_limit() { return _stack_overflow_limit; }
1691 void set_stack_overflow_limit() {
1692 _stack_overflow_limit =
1693 stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1694 }
1695
1696 // Misc. accessors/mutators
1697 void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; }
1698 void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; }
1699 bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; }
1700
1701 #ifndef PRODUCT
1702 void record_jump(address target, address instr, const char* file, int line);
1703 #endif // PRODUCT
1704
1705 // For assembly stub generation
1706 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
1707 #ifndef PRODUCT
1708 static ByteSize jmp_ring_index_offset() { return byte_offset_of(JavaThread, _jmp_ring_index); }
1709 static ByteSize jmp_ring_offset() { return byte_offset_of(JavaThread, _jmp_ring); }
1710 #endif // PRODUCT
1711 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
1712 static ByteSize pending_jni_exception_check_fn_offset() {
1713 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1714 }
1715 static ByteSize last_Java_sp_offset() {
1716 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1717 }
1718 static ByteSize last_Java_pc_offset() {
1719 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1720 }
1721 static ByteSize frame_anchor_offset() {
1722 return byte_offset_of(JavaThread, _anchor);
1723 }
1724 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
1725 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); }
1726 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); }
1727 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
1728 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
1729 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
1730 #if INCLUDE_JVMCI
1731 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1732 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
1733 static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1734 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1735 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1736 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
1737 #endif // INCLUDE_JVMCI
1738 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
1739 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
1740 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
1741 static ByteSize stack_overflow_limit_offset() { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1742 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1743 static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state); }
1744 static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1745 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
1746
1747 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1748 static ByteSize should_post_on_exceptions_flag_offset() {
1749 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1750 }
1751
1752 // Returns the jni environment for this thread
1753 JNIEnv* jni_environment() { return &_jni_environment; }
1754
1755 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1756 JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1757 // Only return NULL if thread is off the thread list; starting to
1758 // exit should not return NULL.
1759 if (thread_from_jni_env->is_terminated()) {
1760 thread_from_jni_env->block_if_vm_exited();
1761 return NULL;
1762 } else {
1763 return thread_from_jni_env;
1764 }
1765 }
1766
1767 // JNI critical regions. These can nest.
1768 bool in_critical() { return _jni_active_critical > 0; }
1769 bool in_last_critical() { return _jni_active_critical == 1; }
1770 inline void enter_critical();
1771 void exit_critical() {
1772 assert(Thread::current() == this, "this must be current thread");
1773 _jni_active_critical--;
1774 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1775 }
1776
1777 // Checked JNI: is the programmer required to check for exceptions, if so specify
1778 // which function name. Returning to a Java frame should implicitly clear the
1779 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1780 // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1781 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1782 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1783 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1784 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1785 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1786
1787 // For deadlock detection
1788 int depth_first_number() { return _depth_first_number; }
1789 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1790
1791 private:
1792 void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1793
1794 public:
1795 MonitorChunk* monitor_chunks() const { return _monitor_chunks; }
1796 void add_monitor_chunk(MonitorChunk* chunk);
1797 void remove_monitor_chunk(MonitorChunk* chunk);
1798 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
1799 void inc_in_deopt_handler() { _in_deopt_handler++; }
1800 void dec_in_deopt_handler() {
1801 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1802 if (_in_deopt_handler > 0) { // robustness
1803 _in_deopt_handler--;
1804 }
1805 }
1806
1807 private:
1808 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1809
1810 public:
1811
1812 // Frame iteration; calls the function f for all frames on the stack
1813 void frames_do(void f(frame*, const RegisterMap*));
1814
1815 // Memory operations
1816 void oops_do(OopClosure* f, CodeBlobClosure* cf);
1817
1818 // Sweeper operations
1819 virtual void nmethods_do(CodeBlobClosure* cf);
1820
1821 // RedefineClasses Support
1822 void metadata_do(void f(Metadata*));
1823
1824 // Misc. operations
1825 char* name() const { return (char*)get_thread_name(); }
1826 void print_on(outputStream* st, bool print_extended_info) const;
1827 void print_on(outputStream* st) const { print_on(st, false); }
1828 void print_value();
1829 void print_thread_state_on(outputStream*) const PRODUCT_RETURN;
1830 void print_thread_state() const PRODUCT_RETURN;
1831 void print_on_error(outputStream* st, char* buf, int buflen) const;
1832 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1833 void verify();
1834 const char* get_thread_name() const;
1835 private:
1836 // factor out low-level mechanics for use in both normal and error cases
1837 const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1838 public:
1839 const char* get_threadgroup_name() const;
1840 const char* get_parent_name() const;
1841
1842 // Accessing frames
1843 frame last_frame() {
1844 _anchor.make_walkable(this);
1845 return pd_last_frame();
1846 }
1847 javaVFrame* last_java_vframe(RegisterMap* reg_map);
1848
1849 // Returns method at 'depth' java or native frames down the stack
1850 // Used for security checks
1851 Klass* security_get_caller_class(int depth);
1852
1853 // Print stack trace in external format
1854 void print_stack_on(outputStream* st);
1855 void print_stack() { print_stack_on(tty); }
1856
1857 // Print stack traces in various internal formats
1858 void trace_stack() PRODUCT_RETURN;
1859 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1860 void trace_frames() PRODUCT_RETURN;
1861 void trace_oops() PRODUCT_RETURN;
1862
1863 // Print an annotated view of the stack frames
1864 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1865 void validate_frame_layout() {
1866 print_frame_layout(0, true);
1867 }
1868
1869 // Returns the number of stack frames on the stack
1870 int depth() const;
1871
1872 // Function for testing deoptimization
1873 void deoptimize();
1874 void make_zombies();
1875
1876 void deoptimized_wrt_marked_nmethods();
1877
1878 public:
1879 // Returns the running thread as a JavaThread
1880 static inline JavaThread* current();
1881
1882 // Returns the active Java thread. Do not use this if you know you are calling
1883 // from a JavaThread, as it's slower than JavaThread::current. If called from
1884 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1885 // operation. You may not want that either.
1886 static JavaThread* active();
1887
1888 inline CompilerThread* as_CompilerThread();
1889
1890 public:
1891 virtual void run();
1892 void thread_main_inner();
1893
1894 private:
1895 GrowableArray<oop>* _array_for_gc;
1896 public:
1897
1898 void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1899
1900 public:
1901 // Thread local information maintained by JVMTI.
1902 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1903 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1904 // getter is used to get this JavaThread's JvmtiThreadState if it has
1905 // one which means NULL can be returned. JvmtiThreadState::state_for()
1906 // is used to get the specified JavaThread's JvmtiThreadState if it has
1907 // one or it allocates a new JvmtiThreadState for the JavaThread and
1908 // returns it. JvmtiThreadState::state_for() will return NULL only if
1909 // the specified JavaThread is exiting.
1910 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1911 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1912
1913 // JVMTI PopFrame support
1914 // Setting and clearing popframe_condition
1915 // All of these enumerated values are bits. popframe_pending
1916 // indicates that a PopFrame() has been requested and not yet been
1917 // completed. popframe_processing indicates that that PopFrame() is in
1918 // the process of being completed. popframe_force_deopt_reexecution_bit
1919 // indicates that special handling is required when returning to a
1920 // deoptimized caller.
1921 enum PopCondition {
1922 popframe_inactive = 0x00,
1923 popframe_pending_bit = 0x01,
1924 popframe_processing_bit = 0x02,
1925 popframe_force_deopt_reexecution_bit = 0x04
1926 };
1927 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1928 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1929 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1930 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1931 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1932 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1933 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1934 void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1935 #ifdef CC_INTERP
1936 bool pop_frame_pending(void) { return ((_popframe_condition & popframe_pending_bit) != 0); }
1937 void clr_pop_frame_pending(void) { _popframe_condition = popframe_inactive; }
1938 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1939 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
1940 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
1941 #endif
1942
1943 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
1944 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
1945 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
1946
1947 private:
1948 // Saved incoming arguments to popped frame.
1949 // Used only when popped interpreted frame returns to deoptimized frame.
1950 void* _popframe_preserved_args;
1951 int _popframe_preserved_args_size;
1952
1953 public:
1954 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
1955 void* popframe_preserved_args();
1956 ByteSize popframe_preserved_args_size();
1957 WordSize popframe_preserved_args_size_in_words();
1958 void popframe_free_preserved_args();
1959
1960
1961 private:
1962 JvmtiThreadState *_jvmti_thread_state;
1963
1964 // Used by the interpreter in fullspeed mode for frame pop, method
1965 // entry, method exit and single stepping support. This field is
1966 // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
1967 // It can be set to zero asynchronously (i.e., without a VM operation
1968 // or a lock) so we have to be very careful.
1969 int _interp_only_mode;
1970
1971 public:
1972 // used by the interpreter for fullspeed debugging support (see above)
1973 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1974 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
1975 int get_interp_only_mode() { return _interp_only_mode; }
1976 void increment_interp_only_mode() { ++_interp_only_mode; }
1977 void decrement_interp_only_mode() { --_interp_only_mode; }
1978
1979 // support for cached flag that indicates whether exceptions need to be posted for this thread
1980 // if this is false, we can avoid deoptimizing when events are thrown
1981 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1982 private:
1983 int _should_post_on_exceptions_flag;
1984
1985 public:
1986 int should_post_on_exceptions_flag() { return _should_post_on_exceptions_flag; }
1987 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
1988
1989 private:
1990 ThreadStatistics *_thread_stat;
1991
1992 public:
1993 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
1994
1995 // Return a blocker object for which this thread is blocked parking.
1996 oop current_park_blocker();
1997
1998 private:
1999 static size_t _stack_size_at_create;
2000
2001 public:
2002 static inline size_t stack_size_at_create(void) {
2003 return _stack_size_at_create;
2004 }
2005 static inline void set_stack_size_at_create(size_t value) {
2006 _stack_size_at_create = value;
2007 }
2008
2009 // Machine dependent stuff
2010 #include OS_CPU_HEADER(thread)
2011
2012 public:
2013 void set_blocked_on_compilation(bool value) {
2014 _blocked_on_compilation = value;
2015 }
2016
2017 bool blocked_on_compilation() {
2018 return _blocked_on_compilation;
2019 }
2020 protected:
2021 bool _blocked_on_compilation;
2022
2023
2024 // JSR166 per-thread parker
2025 private:
2026 Parker* _parker;
2027 public:
2028 Parker* parker() { return _parker; }
2029
2030 // Biased locking support
2031 private:
2032 GrowableArray<MonitorInfo*>* _cached_monitor_info;
2033 public:
2034 GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
2035 void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
2036
2037 // clearing/querying jni attach status
2038 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
2039 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
2040 inline void set_done_attaching_via_jni();
2041 };
2042
2043 // Inline implementation of JavaThread::current
2044 inline JavaThread* JavaThread::current() {
2045 Thread* thread = Thread::current();
2046 assert(thread->is_Java_thread(), "just checking");
2047 return (JavaThread*)thread;
2048 }
2049
2050 inline CompilerThread* JavaThread::as_CompilerThread() {
2051 assert(is_Compiler_thread(), "just checking");
2052 return (CompilerThread*)this;
2053 }
2054
2055 // Dedicated thread to sweep the code cache
2056 class CodeCacheSweeperThread : public JavaThread {
2057 CompiledMethod* _scanned_compiled_method; // nmethod being scanned by the sweeper
2058 public:
2059 CodeCacheSweeperThread();
2060 // Track the nmethod currently being scanned by the sweeper
2061 void set_scanned_compiled_method(CompiledMethod* cm) {
2062 assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value");
2063 _scanned_compiled_method = cm;
2064 }
2065
2066 // Hide sweeper thread from external view.
2067 bool is_hidden_from_external_view() const { return true; }
2068
2069 bool is_Code_cache_sweeper_thread() const { return true; }
2070
2071 // Prevent GC from unloading _scanned_compiled_method
2072 void oops_do(OopClosure* f, CodeBlobClosure* cf);
2073 void nmethods_do(CodeBlobClosure* cf);
2074 };
2075
2076 // A thread used for Compilation.
2077 class CompilerThread : public JavaThread {
2078 friend class VMStructs;
2079 private:
2080 CompilerCounters* _counters;
2081
2082 ciEnv* _env;
2083 CompileLog* _log;
2084 CompileTask* volatile _task; // print_threads_compiling can read this concurrently.
2085 CompileQueue* _queue;
2086 BufferBlob* _buffer_blob;
2087
2088 AbstractCompiler* _compiler;
2089 TimeStamp _idle_time;
2090
2091 public:
2092
2093 static CompilerThread* current();
2094
2095 CompilerThread(CompileQueue* queue, CompilerCounters* counters);
2096 ~CompilerThread();
2097
2098 bool is_Compiler_thread() const { return true; }
2099
2100 virtual bool can_call_java() const;
2101
2102 // Hide native compiler threads from external view.
2103 bool is_hidden_from_external_view() const { return !can_call_java(); }
2104
2105 void set_compiler(AbstractCompiler* c) { _compiler = c; }
2106 AbstractCompiler* compiler() const { return _compiler; }
2107
2108 CompileQueue* queue() const { return _queue; }
2109 CompilerCounters* counters() const { return _counters; }
2110
2111 // Get/set the thread's compilation environment.
2112 ciEnv* env() { return _env; }
2113 void set_env(ciEnv* env) { _env = env; }
2114
2115 BufferBlob* get_buffer_blob() const { return _buffer_blob; }
2116 void set_buffer_blob(BufferBlob* b) { _buffer_blob = b; }
2117
2118 // Get/set the thread's logging information
2119 CompileLog* log() { return _log; }
2120 void init_log(CompileLog* log) {
2121 // Set once, for good.
2122 assert(_log == NULL, "set only once");
2123 _log = log;
2124 }
2125
2126 void start_idle_timer() { _idle_time.update(); }
2127 jlong idle_time_millis() {
2128 return TimeHelper::counter_to_millis(_idle_time.ticks_since_update());
2129 }
2130
2131 #ifndef PRODUCT
2132 private:
2133 IdealGraphPrinter *_ideal_graph_printer;
2134 public:
2135 IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; }
2136 void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2137 #endif
2138
2139 // Get/set the thread's current task
2140 CompileTask* task() { return _task; }
2141 void set_task(CompileTask* task) { _task = task; }
2142 };
2143
2144 inline CompilerThread* CompilerThread::current() {
2145 return JavaThread::current()->as_CompilerThread();
2146 }
2147
2148 // The active thread queue. It also keeps track of the current used
2149 // thread priorities.
2150 class Threads: AllStatic {
2151 friend class VMStructs;
2152 private:
2153 static JavaThread* _thread_list;
2154 static int _number_of_threads;
2155 static int _number_of_non_daemon_threads;
2156 static int _return_code;
2157 static int _thread_claim_parity;
2158 #ifdef ASSERT
2159 static bool _vm_complete;
2160 #endif
2161
2162 static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2163 static void initialize_jsr292_core_classes(TRAPS);
2164
2165 public:
2166 // Thread management
2167 // force_daemon is a concession to JNI, where we may need to add a
2168 // thread to the thread list before allocating its thread object
2169 static void add(JavaThread* p, bool force_daemon = false);
2170 static void remove(JavaThread* p);
2171 static void non_java_threads_do(ThreadClosure* tc);
2172 static void java_threads_do(ThreadClosure* tc);
2173 static void java_threads_and_vm_thread_do(ThreadClosure* tc);
2174 static void threads_do(ThreadClosure* tc);
2175 static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
2176
2177 // Initializes the vm and creates the vm thread
2178 static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
2179 static void convert_vm_init_libraries_to_agents();
2180 static void create_vm_init_libraries();
2181 static void create_vm_init_agents();
2182 static void shutdown_vm_agents();
2183 static bool destroy_vm();
2184 // Supported VM versions via JNI
2185 // Includes JNI_VERSION_1_1
2186 static jboolean is_supported_jni_version_including_1_1(jint version);
2187 // Does not include JNI_VERSION_1_1
2188 static jboolean is_supported_jni_version(jint version);
2189
2190 // The "thread claim parity" provides a way for threads to be claimed
2191 // by parallel worker tasks.
2192 //
2193 // Each thread contains a a "parity" field. A task will claim the
2194 // thread only if its parity field is the same as the global parity,
2195 // which is updated by calling change_thread_claim_parity().
2196 //
2197 // For this to work change_thread_claim_parity() needs to be called
2198 // exactly once in sequential code before starting parallel tasks
2199 // that should claim threads.
2200 //
2201 // New threads get their parity set to 0 and change_thread_claim_parity()
2202 // never set the global parity to 0.
2203 static int thread_claim_parity() { return _thread_claim_parity; }
2204 static void change_thread_claim_parity();
2205 static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
2206
2207 // Apply "f->do_oop" to all root oops in all threads.
2208 // This version may only be called by sequential code.
2209 static void oops_do(OopClosure* f, CodeBlobClosure* cf);
2210 // This version may be called by sequential or parallel code.
2211 static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
2212
2213 // Apply "f->do_oop" to roots in all threads that
2214 // are part of compiled frames
2215 static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf);
2216
2217 static void convert_hcode_pointers();
2218 static void restore_hcode_pointers();
2219
2220 // Sweeper
2221 static void nmethods_do(CodeBlobClosure* cf);
2222
2223 // RedefineClasses support
2224 static void metadata_do(void f(Metadata*));
2225 static void metadata_handles_do(void f(Metadata*));
2226
2227 #ifdef ASSERT
2228 static bool is_vm_complete() { return _vm_complete; }
2229 #endif // ASSERT
2230
2231 // Verification
2232 static void verify();
2233 static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks, bool print_extended_info);
2234 static void print(bool print_stacks, bool internal_format) {
2235 // this function is only used by debug.cpp
2236 print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */, false /* simple format */);
2237 }
2238 static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2239 static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
2240 int buflen, bool* found_current);
2241 static void print_threads_compiling(outputStream* st, char* buf, int buflen);
2242
2243 // Get Java threads that are waiting to enter a monitor.
2244 static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
2245 int count, address monitor);
2246
2247 // Get owning Java thread from the monitor's owner field.
2248 static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
2249 address owner);
2250
2251 // Number of threads on the active threads list
2252 static int number_of_threads() { return _number_of_threads; }
2253 // Number of non-daemon threads on the active threads list
2254 static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; }
2255
2256 // Deoptimizes all frames tied to marked nmethods
2257 static void deoptimized_wrt_marked_nmethods();
2258 };
2259
2260
2261 // Thread iterator
2262 class ThreadClosure: public StackObj {
2263 public:
2264 virtual void do_thread(Thread* thread) = 0;
2265 };
2266
2267 class SignalHandlerMark: public StackObj {
2268 private:
2269 Thread* _thread;
2270 public:
2271 SignalHandlerMark(Thread* t) {
2272 _thread = t;
2273 if (_thread) _thread->enter_signal_handler();
2274 }
2275 ~SignalHandlerMark() {
2276 if (_thread) _thread->leave_signal_handler();
2277 _thread = NULL;
2278 }
2279 };
2280
2281
2282 #endif // SHARE_VM_RUNTIME_THREAD_HPP