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