1 /*
2 * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_VM_RUNTIME_THREAD_HPP
26 #define SHARE_VM_RUNTIME_THREAD_HPP
27
28 #include "jni.h"
29 #include "gc/shared/gcThreadLocalData.hpp"
30 #include "gc/shared/threadLocalAllocBuffer.hpp"
31 #include "memory/allocation.hpp"
32 #include "oops/oop.hpp"
33 #include "prims/jvmtiExport.hpp"
34 #include "runtime/frame.hpp"
35 #include "runtime/globals.hpp"
36 #include "runtime/handshake.hpp"
37 #include "runtime/javaFrameAnchor.hpp"
38 #include "runtime/jniHandles.hpp"
39 #include "runtime/mutexLocker.hpp"
40 #include "runtime/os.hpp"
41 #include "runtime/osThread.hpp"
42 #include "runtime/park.hpp"
43 #include "runtime/safepoint.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 JvmtiGetLoadedClassesClosure;
67 class ThreadStatistics;
68 class ConcurrentLocksDump;
69 class ParkEvent;
70 class Parker;
71
72 class ciEnv;
73 class CompileThread;
74 class CompileLog;
75 class CompileTask;
76 class CompileQueue;
77 class CompilerCounters;
78 class vframeArray;
79
80 class DeoptResourceMark;
81 class jvmtiDeferredLocalVariableSet;
82
83 class GCTaskQueue;
84 class ThreadClosure;
85 class IdealGraphPrinter;
86
87 class Metadata;
88 template <class T, MEMFLAGS F> class ChunkedList;
89 typedef ChunkedList<Metadata*, mtInternal> MetadataOnStackBuffer;
90
91 DEBUG_ONLY(class ResourceMark;)
92
93 class WorkerThread;
94
95 // Class hierarchy
96 // - Thread
97 // - NamedThread
98 // - VMThread
99 // - ConcurrentGCThread
100 // - WorkerThread
101 // - GangWorker
102 // - GCTaskThread
103 // - JavaThread
104 // - various subclasses eg CompilerThread, ServiceThread
105 // - WatcherThread
106
107 class Thread: public ThreadShadow {
108 friend class VMStructs;
109 friend class JVMCIVMStructs;
110 private:
111
112 #ifndef USE_LIBRARY_BASED_TLS_ONLY
113 // Current thread is maintained as a thread-local variable
114 static THREAD_LOCAL_DECL Thread* _thr_current;
115 #endif
116
117 private:
118 // Thread local data area available to the GC. The internal
119 // structure and contents of this data area is GC-specific.
120 // Only GC and GC barrier code should access this data area.
121 GCThreadLocalData _gc_data;
122
123 public:
124 static ByteSize gc_data_offset() {
125 return byte_offset_of(Thread, _gc_data);
126 }
127
128 template <typename T> T* gc_data() {
129 STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data));
130 return reinterpret_cast<T*>(&_gc_data);
131 }
132
133 // Exception handling
134 // (Note: _pending_exception and friends are in ThreadShadow)
135 //oop _pending_exception; // pending exception for current thread
136 // const char* _exception_file; // file information for exception (debugging only)
137 // int _exception_line; // line information for exception (debugging only)
138 protected:
139 // Support for forcing alignment of thread objects for biased locking
140 void* _real_malloc_address;
141
142 // JavaThread lifecycle support:
143 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
144 friend class ScanHazardPtrGatherProtectedThreadsClosure; // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
145 friend class ScanHazardPtrGatherThreadsListClosure; // for get_threads_hazard_ptr(), untag_hazard_ptr() access
146 friend class ScanHazardPtrPrintMatchingThreadsClosure; // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
147 friend class ThreadsSMRSupport; // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
148
149 ThreadsList* volatile _threads_hazard_ptr;
150 SafeThreadsListPtr* _threads_list_ptr;
151 ThreadsList* cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
152 ThreadsList* get_threads_hazard_ptr();
153 void set_threads_hazard_ptr(ThreadsList* new_list);
154 static bool is_hazard_ptr_tagged(ThreadsList* list) {
155 return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
156 }
157 static ThreadsList* tag_hazard_ptr(ThreadsList* list) {
158 return (ThreadsList*)(intptr_t(list) | intptr_t(1));
159 }
160 static ThreadsList* untag_hazard_ptr(ThreadsList* list) {
161 return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
162 }
163 // This field is enabled via -XX:+EnableThreadSMRStatistics:
164 uint _nested_threads_hazard_ptr_cnt;
165 void dec_nested_threads_hazard_ptr_cnt() {
166 assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
167 _nested_threads_hazard_ptr_cnt--;
168 }
169 void inc_nested_threads_hazard_ptr_cnt() {
170 _nested_threads_hazard_ptr_cnt++;
171 }
172 uint nested_threads_hazard_ptr_cnt() {
173 return _nested_threads_hazard_ptr_cnt;
174 }
175
176 public:
177 void* operator new(size_t size) throw() { return allocate(size, true); }
178 void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
179 return allocate(size, false); }
180 void operator delete(void* p);
181
182 protected:
183 static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
184 private:
185
186 // ***************************************************************
187 // Suspend and resume support
188 // ***************************************************************
189 //
190 // VM suspend/resume no longer exists - it was once used for various
191 // things including safepoints but was deprecated and finally removed
192 // in Java 7. Because VM suspension was considered "internal" Java-level
193 // suspension was considered "external", and this legacy naming scheme
194 // remains.
195 //
196 // External suspend/resume requests come from JVM_SuspendThread,
197 // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
198 // ResumeThread. External
199 // suspend requests cause _external_suspend to be set and external
200 // resume requests cause _external_suspend to be cleared.
201 // External suspend requests do not nest on top of other external
202 // suspend requests. The higher level APIs reject suspend requests
203 // for already suspended threads.
204 //
205 // The external_suspend
206 // flag is checked by has_special_runtime_exit_condition() and java thread
207 // will self-suspend when handle_special_runtime_exit_condition() is
208 // called. Most uses of the _thread_blocked state in JavaThreads are
209 // considered the same as being externally suspended; if the blocking
210 // condition lifts, the JavaThread will self-suspend. Other places
211 // where VM checks for external_suspend include:
212 // + mutex granting (do not enter monitors when thread is suspended)
213 // + state transitions from _thread_in_native
214 //
215 // In general, java_suspend() does not wait for an external suspend
216 // request to complete. When it returns, the only guarantee is that
217 // the _external_suspend field is true.
218 //
219 // wait_for_ext_suspend_completion() is used to wait for an external
220 // suspend request to complete. External suspend requests are usually
221 // followed by some other interface call that requires the thread to
222 // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
223 // the interface that requires quiescence, we give the JavaThread a
224 // chance to self-suspend before we need it to be quiescent. This
225 // improves overall suspend/query performance.
226 //
227 // _suspend_flags controls the behavior of java_ suspend/resume.
228 // It must be set under the protection of SR_lock. Read from the flag is
229 // OK without SR_lock as long as the value is only used as a hint.
230 // (e.g., check _external_suspend first without lock and then recheck
231 // inside SR_lock and finish the suspension)
232 //
233 // _suspend_flags is also overloaded for other "special conditions" so
234 // that a single check indicates whether any special action is needed
235 // eg. for async exceptions.
236 // -------------------------------------------------------------------
237 // Notes:
238 // 1. The suspend/resume logic no longer uses ThreadState in OSThread
239 // but we still update its value to keep other part of the system (mainly
240 // JVMTI) happy. ThreadState is legacy code (see notes in
241 // osThread.hpp).
242 //
243 // 2. It would be more natural if set_external_suspend() is private and
244 // part of java_suspend(), but that probably would affect the suspend/query
245 // performance. Need more investigation on this.
246
247 // suspend/resume lock: used for self-suspend
248 Monitor* _SR_lock;
249
250 protected:
251 enum SuspendFlags {
252 // NOTE: avoid using the sign-bit as cc generates different test code
253 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
254
255 _external_suspend = 0x20000000U, // thread is asked to self suspend
256 _ext_suspended = 0x40000000U, // thread has self-suspended
257 _deopt_suspend = 0x10000000U, // thread needs to self suspend for deopt
258
259 _has_async_exception = 0x00000001U, // there is a pending async exception
260 _critical_native_unlock = 0x00000002U, // Must call back to unlock JNI critical lock
261
262 _trace_flag = 0x00000004U // call tracing backend
263 };
264
265 // various suspension related flags - atomically updated
266 // overloaded for async exception checking in check_special_condition_for_native_trans.
267 volatile uint32_t _suspend_flags;
268
269 private:
270 int _num_nested_signal;
271
272 DEBUG_ONLY(bool _suspendible_thread;)
273
274 public:
275 void enter_signal_handler() { _num_nested_signal++; }
276 void leave_signal_handler() { _num_nested_signal--; }
277 bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
278
279 #ifdef ASSERT
280 void set_suspendible_thread() {
281 _suspendible_thread = true;
282 }
283
284 void clear_suspendible_thread() {
285 _suspendible_thread = false;
286 }
287
288 bool is_suspendible_thread() { return _suspendible_thread; }
289 #endif
290
291 private:
292 // Active_handles points to a block of handles
293 JNIHandleBlock* _active_handles;
294
295 // One-element thread local free list
296 JNIHandleBlock* _free_handle_block;
297
298 // Point to the last handle mark
299 HandleMark* _last_handle_mark;
300
301 // The parity of the last strong_roots iteration in which this thread was
302 // claimed as a task.
303 int _oops_do_parity;
304
305 // Support for GlobalCounter
306 private:
307 volatile uintx _rcu_counter;
308 public:
309 volatile uintx* get_rcu_counter() {
310 return &_rcu_counter;
311 }
312
313 public:
314 void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; }
315 HandleMark* last_handle_mark() const { return _last_handle_mark; }
316 private:
317
318 // debug support for checking if code does allow safepoints or not
319 // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on
320 // mutex, or blocking on an object synchronizer (Java locking).
321 // If !allow_safepoint(), then an assertion failure will happen in any of the above cases
322 // If !allow_allocation(), then an assertion failure will happen during allocation
323 // (Hence, !allow_safepoint() => !allow_allocation()).
324 //
325 // The two classes NoSafepointVerifier and No_Allocation_Verifier are used to set these counters.
326 //
327 NOT_PRODUCT(int _allow_safepoint_count;) // If 0, thread allow a safepoint to happen
328 debug_only(int _allow_allocation_count;) // If 0, the thread is allowed to allocate oops.
329
330 // Used by SkipGCALot class.
331 NOT_PRODUCT(bool _skip_gcalot;) // Should we elide gc-a-lot?
332
333 friend class NoAllocVerifier;
334 friend class NoSafepointVerifier;
335 friend class PauseNoSafepointVerifier;
336 friend class GCLocker;
337
338 volatile void* _polling_page; // Thread local polling page
339
340 ThreadLocalAllocBuffer _tlab; // Thread-local eden
341 jlong _allocated_bytes; // Cumulative number of bytes allocated on
342 // the Java heap
343 ThreadHeapSampler _heap_sampler; // For use when sampling the memory.
344
345 ThreadStatisticalInfo _statistical_info; // Statistics about the thread
346
347 JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;) // Thread-local data for jfr
348
349 int _vm_operation_started_count; // VM_Operation support
350 int _vm_operation_completed_count; // VM_Operation support
351
352 ObjectMonitor* _current_pending_monitor; // ObjectMonitor this thread
353 // is waiting to lock
354 bool _current_pending_monitor_is_from_java; // locking is from Java code
355
356 // ObjectMonitor on which this thread called Object.wait()
357 ObjectMonitor* _current_waiting_monitor;
358
359 // Private thread-local objectmonitor list - a simple cache organized as a SLL.
360 public:
361 ObjectMonitor* omFreeList;
362 int omFreeCount; // length of omFreeList
363 int omFreeProvision; // reload chunk size
364 ObjectMonitor* omInUseList; // SLL to track monitors in circulation
365 int omInUseCount; // length of omInUseList
366
367 #ifdef ASSERT
368 private:
369 bool _visited_for_critical_count;
370
371 public:
372 void set_visited_for_critical_count(bool z) { _visited_for_critical_count = z; }
373 bool was_visited_for_critical_count() const { return _visited_for_critical_count; }
374 #endif
375
376 public:
377 enum {
378 is_definitely_current_thread = true
379 };
380
381 // Constructor
382 Thread();
383 virtual ~Thread();
384
385 // Manage Thread::current()
386 void initialize_thread_current();
387 void clear_thread_current(); // TLS cleanup needed before threads terminate
388
389 public:
390 // thread entry point
391 virtual void run();
392
393 // Testers
394 virtual bool is_VM_thread() const { return false; }
395 virtual bool is_Java_thread() const { return false; }
396 virtual bool is_Compiler_thread() const { return false; }
397 virtual bool is_Code_cache_sweeper_thread() const { return false; }
398 virtual bool is_hidden_from_external_view() const { return false; }
399 virtual bool is_jvmti_agent_thread() const { return false; }
400 // True iff the thread can perform GC operations at a safepoint.
401 // Generally will be true only of VM thread and parallel GC WorkGang
402 // threads.
403 virtual bool is_GC_task_thread() const { return false; }
404 virtual bool is_Watcher_thread() const { return false; }
405 virtual bool is_ConcurrentGC_thread() const { return false; }
406 virtual bool is_Named_thread() const { return false; }
407 virtual bool is_Worker_thread() const { return false; }
408
409 // Can this thread make Java upcalls
410 virtual bool can_call_java() const { return false; }
411
412 // Casts
413 virtual WorkerThread* as_Worker_thread() const { return NULL; }
414
415 virtual char* name() const { return (char*)"Unknown thread"; }
416
417 // Returns the current thread (ASSERTS if NULL)
418 static inline Thread* current();
419 // Returns the current thread, or NULL if not attached
420 static inline Thread* current_or_null();
421 // Returns the current thread, or NULL if not attached, and is
422 // safe for use from signal-handlers
423 static inline Thread* current_or_null_safe();
424
425 // Common thread operations
426 #ifdef ASSERT
427 static void check_for_dangling_thread_pointer(Thread *thread);
428 #endif
429 static void set_priority(Thread* thread, ThreadPriority priority);
430 static ThreadPriority get_priority(const Thread* const thread);
431 static void start(Thread* thread);
432 static void interrupt(Thread* thr);
433 static bool is_interrupted(Thread* thr, bool clear_interrupted);
434
435 void set_native_thread_name(const char *name) {
436 assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
437 os::set_native_thread_name(name);
438 }
439
440 ObjectMonitor** omInUseList_addr() { return (ObjectMonitor **)&omInUseList; }
441 Monitor* SR_lock() const { return _SR_lock; }
442
443 bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
444
445 inline void set_suspend_flag(SuspendFlags f);
446 inline void clear_suspend_flag(SuspendFlags f);
447
448 inline void set_has_async_exception();
449 inline void clear_has_async_exception();
450
451 bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
452
453 inline void set_critical_native_unlock();
454 inline void clear_critical_native_unlock();
455
456 inline void set_trace_flag();
457 inline void clear_trace_flag();
458
459 // Support for Unhandled Oop detection
460 // Add the field for both, fastdebug and debug, builds to keep
461 // Thread's fields layout the same.
462 // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
463 #ifdef CHECK_UNHANDLED_OOPS
464 private:
465 UnhandledOops* _unhandled_oops;
466 #elif defined(ASSERT)
467 private:
468 void* _unhandled_oops;
469 #endif
470 #ifdef CHECK_UNHANDLED_OOPS
471 public:
472 UnhandledOops* unhandled_oops() { return _unhandled_oops; }
473 // Mark oop safe for gc. It may be stack allocated but won't move.
474 void allow_unhandled_oop(oop *op) {
475 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
476 }
477 // Clear oops at safepoint so crashes point to unhandled oop violator
478 void clear_unhandled_oops() {
479 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
480 }
481 #endif // CHECK_UNHANDLED_OOPS
482
483 public:
484 #ifndef PRODUCT
485 bool skip_gcalot() { return _skip_gcalot; }
486 void set_skip_gcalot(bool v) { _skip_gcalot = v; }
487 #endif
488
489 // Installs a pending exception to be inserted later
490 static void send_async_exception(oop thread_oop, oop java_throwable);
491
492 // Resource area
493 ResourceArea* resource_area() const { return _resource_area; }
494 void set_resource_area(ResourceArea* area) { _resource_area = area; }
495
496 OSThread* osthread() const { return _osthread; }
497 void set_osthread(OSThread* thread) { _osthread = thread; }
498
499 // JNI handle support
500 JNIHandleBlock* active_handles() const { return _active_handles; }
501 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
502 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
503 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
504
505 // Internal handle support
506 HandleArea* handle_area() const { return _handle_area; }
507 void set_handle_area(HandleArea* area) { _handle_area = area; }
508
509 GrowableArray<Metadata*>* metadata_handles() const { return _metadata_handles; }
510 void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
511
512 // Thread-Local Allocation Buffer (TLAB) support
513 ThreadLocalAllocBuffer& tlab() { return _tlab; }
514 void initialize_tlab() {
515 if (UseTLAB) {
516 tlab().initialize();
517 }
518 }
519
520 jlong allocated_bytes() { return _allocated_bytes; }
521 void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
522 void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
523 inline jlong cooked_allocated_bytes();
524
525 ThreadHeapSampler& heap_sampler() { return _heap_sampler; }
526
527 ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
528
529 JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
530
531 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; }
532
533 // VM operation support
534 int vm_operation_ticket() { return ++_vm_operation_started_count; }
535 int vm_operation_completed_count() { return _vm_operation_completed_count; }
536 void increment_vm_operation_completed_count() { _vm_operation_completed_count++; }
537
538 // For tracking the heavyweight monitor the thread is pending on.
539 ObjectMonitor* current_pending_monitor() {
540 return _current_pending_monitor;
541 }
542 void set_current_pending_monitor(ObjectMonitor* monitor) {
543 _current_pending_monitor = monitor;
544 }
545 void set_current_pending_monitor_is_from_java(bool from_java) {
546 _current_pending_monitor_is_from_java = from_java;
547 }
548 bool current_pending_monitor_is_from_java() {
549 return _current_pending_monitor_is_from_java;
550 }
551
552 // For tracking the ObjectMonitor on which this thread called Object.wait()
553 ObjectMonitor* current_waiting_monitor() {
554 return _current_waiting_monitor;
555 }
556 void set_current_waiting_monitor(ObjectMonitor* monitor) {
557 _current_waiting_monitor = monitor;
558 }
559
560 // GC support
561 // Apply "f->do_oop" to all root oops in "this".
562 // Used by JavaThread::oops_do.
563 // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
564 virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
565
566 // Handles the parallel case for the method below.
567 private:
568 bool claim_oops_do_par_case(int collection_parity);
569 public:
570 // Requires that "collection_parity" is that of the current roots
571 // iteration. If "is_par" is false, sets the parity of "this" to
572 // "collection_parity", and returns "true". If "is_par" is true,
573 // uses an atomic instruction to set the current threads parity to
574 // "collection_parity", if it is not already. Returns "true" iff the
575 // calling thread does the update, this indicates that the calling thread
576 // has claimed the thread's stack as a root groop in the current
577 // collection.
578 bool claim_oops_do(bool is_par, int collection_parity) {
579 if (!is_par) {
580 _oops_do_parity = collection_parity;
581 return true;
582 } else {
583 return claim_oops_do_par_case(collection_parity);
584 }
585 }
586
587 // jvmtiRedefineClasses support
588 void metadata_handles_do(void f(Metadata*));
589
590 // Used by fast lock support
591 virtual bool is_lock_owned(address adr) const;
592
593 // Check if address is in the stack of the thread (not just for locks).
594 // Warning: the method can only be used on the running thread
595 bool is_in_stack(address adr) const;
596 // Check if address is in the usable part of the stack (excludes protected
597 // guard pages)
598 bool is_in_usable_stack(address adr) const;
599
600 // Sets this thread as starting thread. Returns failure if thread
601 // creation fails due to lack of memory, too many threads etc.
602 bool set_as_starting_thread();
603
604 protected:
605 // OS data associated with the thread
606 OSThread* _osthread; // Platform-specific thread information
607
608 // Thread local resource area for temporary allocation within the VM
609 ResourceArea* _resource_area;
610
611 DEBUG_ONLY(ResourceMark* _current_resource_mark;)
612
613 // Thread local handle area for allocation of handles within the VM
614 HandleArea* _handle_area;
615 GrowableArray<Metadata*>* _metadata_handles;
616
617 // Support for stack overflow handling, get_thread, etc.
618 address _stack_base;
619 size_t _stack_size;
620 uintptr_t _self_raw_id; // used by get_thread (mutable)
621 int _lgrp_id;
622
623 volatile void** polling_page_addr() { return &_polling_page; }
624
625 public:
626 // Stack overflow support
627 address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
628 void set_stack_base(address base) { _stack_base = base; }
629 size_t stack_size() const { return _stack_size; }
630 void set_stack_size(size_t size) { _stack_size = size; }
631 address stack_end() const { return stack_base() - stack_size(); }
632 void record_stack_base_and_size();
633
634 bool on_local_stack(address adr) const {
635 // QQQ this has knowledge of direction, ought to be a stack method
636 return (_stack_base >= adr && adr >= stack_end());
637 }
638
639 uintptr_t self_raw_id() { return _self_raw_id; }
640 void set_self_raw_id(uintptr_t value) { _self_raw_id = value; }
641
642 int lgrp_id() const { return _lgrp_id; }
643 void set_lgrp_id(int value) { _lgrp_id = value; }
644
645 // Printing
646 void print_on(outputStream* st, bool print_extended_info) const;
647 virtual void print_on(outputStream* st) const { print_on(st, false); }
648 void print() const { print_on(tty); }
649 virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
650 void print_value_on(outputStream* st) const;
651
652 // Debug-only code
653 #ifdef ASSERT
654 private:
655 // Deadlock detection support for Mutex locks. List of locks own by thread.
656 Monitor* _owned_locks;
657 // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
658 // thus the friendship
659 friend class Mutex;
660 friend class Monitor;
661
662 public:
663 void print_owned_locks_on(outputStream* st) const;
664 void print_owned_locks() const { print_owned_locks_on(tty); }
665 Monitor* owned_locks() const { return _owned_locks; }
666 bool owns_locks() const { return owned_locks() != NULL; }
667 bool owns_locks_but_compiled_lock() const;
668 int oops_do_parity() const { return _oops_do_parity; }
669
670 // Deadlock detection
671 bool allow_allocation() { return _allow_allocation_count == 0; }
672 ResourceMark* current_resource_mark() { return _current_resource_mark; }
673 void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
674 #endif
675
676 void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN;
677
678 private:
679 volatile int _jvmti_env_iteration_count;
680
681 public:
682 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; }
683 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; }
684 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; }
685
686 // Code generation
687 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file); }
688 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line); }
689 static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles); }
690
691 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base); }
692 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size); }
693
694 static ByteSize polling_page_offset() { return byte_offset_of(Thread, _polling_page); }
695
696 #define TLAB_FIELD_OFFSET(name) \
697 static ByteSize tlab_##name##_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::name##_offset(); }
698
699 TLAB_FIELD_OFFSET(start)
700 TLAB_FIELD_OFFSET(end)
701 TLAB_FIELD_OFFSET(top)
702 TLAB_FIELD_OFFSET(pf_top)
703 TLAB_FIELD_OFFSET(size) // desired_size
704 TLAB_FIELD_OFFSET(refill_waste_limit)
705 TLAB_FIELD_OFFSET(number_of_refills)
706 TLAB_FIELD_OFFSET(fast_refill_waste)
707 TLAB_FIELD_OFFSET(slow_allocations)
708
709 #undef TLAB_FIELD_OFFSET
710
711 static ByteSize allocated_bytes_offset() { return byte_offset_of(Thread, _allocated_bytes); }
712
713 JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
714
715 public:
716 volatile intptr_t _Stalled;
717 volatile int _TypeTag;
718 ParkEvent * _ParkEvent; // for synchronized()
719 ParkEvent * _SleepEvent; // for Thread.sleep
720 ParkEvent * _MutexEvent; // for native internal Mutex/Monitor
721 ParkEvent * _MuxEvent; // for low-level muxAcquire-muxRelease
722 int NativeSyncRecursion; // diagnostic
723
724 volatile int _OnTrap; // Resume-at IP delta
725 jint _hashStateW; // Marsaglia Shift-XOR thread-local RNG
726 jint _hashStateX; // thread-specific hashCode generator state
727 jint _hashStateY;
728 jint _hashStateZ;
729 void * _schedctl;
730
731
732 volatile jint rng[4]; // RNG for spin loop
733
734 // Low-level leaf-lock primitives used to implement synchronization
735 // and native monitor-mutex infrastructure.
736 // Not for general synchronization use.
737 static void SpinAcquire(volatile int * Lock, const char * Name);
738 static void SpinRelease(volatile int * Lock);
739 static void muxAcquire(volatile intptr_t * Lock, const char * Name);
740 static void muxAcquireW(volatile intptr_t * Lock, ParkEvent * ev);
741 static void muxRelease(volatile intptr_t * Lock);
742 };
743
744 // Inline implementation of Thread::current()
745 inline Thread* Thread::current() {
746 Thread* current = current_or_null();
747 assert(current != NULL, "Thread::current() called on detached thread");
748 return current;
749 }
750
751 inline Thread* Thread::current_or_null() {
752 #ifndef USE_LIBRARY_BASED_TLS_ONLY
753 return _thr_current;
754 #else
755 if (ThreadLocalStorage::is_initialized()) {
756 return ThreadLocalStorage::thread();
757 }
758 return NULL;
759 #endif
760 }
761
762 inline Thread* Thread::current_or_null_safe() {
763 if (ThreadLocalStorage::is_initialized()) {
764 return ThreadLocalStorage::thread();
765 }
766 return NULL;
767 }
768
769 // Name support for threads. non-JavaThread subclasses with multiple
770 // uniquely named instances should derive from this.
771 class NamedThread: public Thread {
772 friend class VMStructs;
773 enum {
774 max_name_len = 64
775 };
776 private:
777 char* _name;
778 // log JavaThread being processed by oops_do
779 JavaThread* _processed_thread;
780 uint _gc_id; // The current GC id when a thread takes part in GC
781
782 public:
783 NamedThread();
784 ~NamedThread();
785 // May only be called once per thread.
786 void set_name(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
787 void initialize_named_thread();
788 virtual bool is_Named_thread() const { return true; }
789 virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
790 JavaThread *processed_thread() { return _processed_thread; }
791 void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
792 virtual void print_on(outputStream* st) const;
793
794 void set_gc_id(uint gc_id) { _gc_id = gc_id; }
795 uint gc_id() { return _gc_id; }
796 };
797
798 // Worker threads are named and have an id of an assigned work.
799 class WorkerThread: public NamedThread {
800 private:
801 uint _id;
802 public:
803 WorkerThread() : _id(0) { }
804 virtual bool is_Worker_thread() const { return true; }
805
806 virtual WorkerThread* as_Worker_thread() const {
807 assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
808 return (WorkerThread*) this;
809 }
810
811 void set_id(uint work_id) { _id = work_id; }
812 uint id() const { return _id; }
813 };
814
815 // A single WatcherThread is used for simulating timer interrupts.
816 class WatcherThread: public Thread {
817 friend class VMStructs;
818 public:
819 virtual void run();
820
821 private:
822 static WatcherThread* _watcher_thread;
823
824 static bool _startable;
825 // volatile due to at least one lock-free read
826 volatile static bool _should_terminate;
827 public:
828 enum SomeConstants {
829 delay_interval = 10 // interrupt delay in milliseconds
830 };
831
832 // Constructor
833 WatcherThread();
834
835 // No destruction allowed
836 ~WatcherThread() {
837 guarantee(false, "WatcherThread deletion must fix the race with VM termination");
838 }
839
840 // Tester
841 bool is_Watcher_thread() const { return true; }
842
843 // Printing
844 char* name() const { return (char*)"VM Periodic Task Thread"; }
845 void print_on(outputStream* st) const;
846 void unpark();
847
848 // Returns the single instance of WatcherThread
849 static WatcherThread* watcher_thread() { return _watcher_thread; }
850
851 // Create and start the single instance of WatcherThread, or stop it on shutdown
852 static void start();
853 static void stop();
854 // Only allow start once the VM is sufficiently initialized
855 // Otherwise the first task to enroll will trigger the start
856 static void make_startable();
857 private:
858 int sleep() const;
859 };
860
861
862 class CompilerThread;
863
864 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
865
866 class JavaThread: public Thread {
867 friend class VMStructs;
868 friend class JVMCIVMStructs;
869 friend class WhiteBox;
870 private:
871 JavaThread* _next; // The next thread in the Threads list
872 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
873 oop _threadObj; // The Java level thread object
874
875 #ifdef ASSERT
876 private:
877 int _java_call_counter;
878
879 public:
880 int java_call_counter() { return _java_call_counter; }
881 void inc_java_call_counter() { _java_call_counter++; }
882 void dec_java_call_counter() {
883 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
884 _java_call_counter--;
885 }
886 private: // restore original namespace restriction
887 #endif // ifdef ASSERT
888
889 #ifndef PRODUCT
890 public:
891 enum {
892 jump_ring_buffer_size = 16
893 };
894 private: // restore original namespace restriction
895 #endif
896
897 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
898
899 ThreadFunction _entry_point;
900
901 JNIEnv _jni_environment;
902
903 // Deopt support
904 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
905
906 intptr_t* _must_deopt_id; // id of frame that needs to be deopted once we
907 // transition out of native
908 CompiledMethod* _deopt_nmethod; // CompiledMethod that is currently being deoptimized
909 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
910 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
911 // Because deoptimization is lazy we must save jvmti requests to set locals
912 // in compiled frames until we deoptimize and we have an interpreter frame.
913 // This holds the pointer to array (yeah like there might be more than one) of
914 // description of compiled vframes that have locals that need to be updated.
915 GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
916
917 // Handshake value for fixing 6243940. We need a place for the i2c
918 // adapter to store the callee Method*. This value is NEVER live
919 // across a gc point so it does NOT have to be gc'd
920 // The handshake is open ended since we can't be certain that it will
921 // be NULLed. This is because we rarely ever see the race and end up
922 // in handle_wrong_method which is the backend of the handshake. See
923 // code in i2c adapters and handle_wrong_method.
924
925 Method* _callee_target;
926
927 // Used to pass back results to the interpreter or generated code running Java code.
928 oop _vm_result; // oop result is GC-preserved
929 Metadata* _vm_result_2; // non-oop result
930
931 // See ReduceInitialCardMarks: this holds the precise space interval of
932 // the most recent slow path allocation for which compiled code has
933 // elided card-marks for performance along the fast-path.
934 MemRegion _deferred_card_mark;
935
936 MonitorChunk* _monitor_chunks; // Contains the off stack monitors
937 // allocated during deoptimization
938 // and by JNI_MonitorEnter/Exit
939
940 // Async. requests support
941 enum AsyncRequests {
942 _no_async_condition = 0,
943 _async_exception,
944 _async_unsafe_access_error
945 };
946 AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
947 oop _pending_async_exception;
948
949 // Safepoint support
950 public: // Expose _thread_state for SafeFetchInt()
951 volatile JavaThreadState _thread_state;
952 private:
953 ThreadSafepointState *_safepoint_state; // Holds information about a thread during a safepoint
954 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
955
956 // JavaThread termination support
957 enum TerminatedTypes {
958 _not_terminated = 0xDEAD - 2,
959 _thread_exiting, // JavaThread::exit() has been called for this thread
960 _thread_terminated, // JavaThread is removed from thread list
961 _vm_exited // JavaThread is still executing native code, but VM is terminated
962 // only VM_Exit can set _vm_exited
963 };
964
965 // In general a JavaThread's _terminated field transitions as follows:
966 //
967 // _not_terminated => _thread_exiting => _thread_terminated
968 //
969 // _vm_exited is a special value to cover the case of a JavaThread
970 // executing native code after the VM itself is terminated.
971 volatile TerminatedTypes _terminated;
972 // suspend/resume support
973 volatile bool _suspend_equivalent; // Suspend equivalent condition
974 jint _in_deopt_handler; // count of deoptimization
975 // handlers thread is in
976 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
977 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
978 // never locked) when throwing an exception. Used by interpreter only.
979
980 // JNI attach states:
981 enum JNIAttachStates {
982 _not_attaching_via_jni = 1, // thread is not attaching via JNI
983 _attaching_via_jni, // thread is attaching via JNI
984 _attached_via_jni // thread has attached via JNI
985 };
986
987 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
988 // A native thread that is attaching via JNI starts with a value
989 // of _attaching_via_jni and transitions to _attached_via_jni.
990 volatile JNIAttachStates _jni_attach_state;
991
992 public:
993 // State of the stack guard pages for this thread.
994 enum StackGuardState {
995 stack_guard_unused, // not needed
996 stack_guard_reserved_disabled,
997 stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
998 stack_guard_enabled // enabled
999 };
1000
1001 private:
1002
1003 #if INCLUDE_JVMCI
1004 // The _pending_* fields below are used to communicate extra information
1005 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
1006
1007 // Communicates the DeoptReason and DeoptAction of the uncommon trap
1008 int _pending_deoptimization;
1009
1010 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
1011 // before the monitor has been acquired.
1012 bool _pending_monitorenter;
1013
1014 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
1015 bool _pending_transfer_to_interpreter;
1016
1017 // Guard for re-entrant call to JVMCIRuntime::adjust_comp_level
1018 bool _adjusting_comp_level;
1019
1020 // An id of a speculation that JVMCI compiled code can use to further describe and
1021 // uniquely identify the speculative optimization guarded by the uncommon trap
1022 long _pending_failed_speculation;
1023
1024 // These fields are mutually exclusive in terms of live ranges.
1025 union {
1026 // Communicates the pc at which the most recent implicit exception occurred
1027 // from the signal handler to a deoptimization stub.
1028 address _implicit_exception_pc;
1029
1030 // Communicates an alternative call target to an i2c stub from a JavaCall .
1031 address _alternate_call_target;
1032 } _jvmci;
1033
1034 // Support for high precision, thread sensitive counters in JVMCI compiled code.
1035 jlong* _jvmci_counters;
1036
1037 public:
1038 static jlong* _jvmci_old_thread_counters;
1039 static void collect_counters(typeArrayOop array);
1040 private:
1041 #endif // INCLUDE_JVMCI
1042
1043 StackGuardState _stack_guard_state;
1044
1045 // Precompute the limit of the stack as used in stack overflow checks.
1046 // We load it from here to simplify the stack overflow check in assembly.
1047 address _stack_overflow_limit;
1048 address _reserved_stack_activation;
1049
1050 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1051 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1052 // code)
1053 volatile oop _exception_oop; // Exception thrown in compiled code
1054 volatile address _exception_pc; // PC where exception happened
1055 volatile address _exception_handler_pc; // PC for handler of exception
1056 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
1057
1058 private:
1059 // support for JNI critical regions
1060 jint _jni_active_critical; // count of entries into JNI critical region
1061
1062 // Checked JNI: function name requires exception check
1063 char* _pending_jni_exception_check_fn;
1064
1065 // For deadlock detection.
1066 int _depth_first_number;
1067
1068 // JVMTI PopFrame support
1069 // This is set to popframe_pending to signal that top Java frame should be popped immediately
1070 int _popframe_condition;
1071
1072 // If reallocation of scalar replaced objects fails, we throw OOM
1073 // and during exception propagation, pop the top
1074 // _frames_to_pop_failed_realloc frames, the ones that reference
1075 // failed reallocations.
1076 int _frames_to_pop_failed_realloc;
1077
1078 #ifndef PRODUCT
1079 int _jmp_ring_index;
1080 struct {
1081 // We use intptr_t instead of address so debugger doesn't try and display strings
1082 intptr_t _target;
1083 intptr_t _instruction;
1084 const char* _file;
1085 int _line;
1086 } _jmp_ring[jump_ring_buffer_size];
1087 #endif // PRODUCT
1088
1089 friend class VMThread;
1090 friend class ThreadWaitTransition;
1091 friend class VM_Exit;
1092
1093 void initialize(); // Initialized the instance variables
1094
1095 public:
1096 // Constructor
1097 JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1098 JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1099 ~JavaThread();
1100
1101 #ifdef ASSERT
1102 // verify this JavaThread hasn't be published in the Threads::list yet
1103 void verify_not_published();
1104 #endif
1105
1106 //JNI functiontable getter/setter for JVMTI jni function table interception API.
1107 void set_jni_functions(struct JNINativeInterface_* functionTable) {
1108 _jni_environment.functions = functionTable;
1109 }
1110 struct JNINativeInterface_* get_jni_functions() {
1111 return (struct JNINativeInterface_ *)_jni_environment.functions;
1112 }
1113
1114 // This function is called at thread creation to allow
1115 // platform specific thread variables to be initialized.
1116 void cache_global_variables();
1117
1118 // Executes Shutdown.shutdown()
1119 void invoke_shutdown_hooks();
1120
1121 // Cleanup on thread exit
1122 enum ExitType {
1123 normal_exit,
1124 jni_detach
1125 };
1126 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1127
1128 void cleanup_failed_attach_current_thread();
1129
1130 // Testers
1131 virtual bool is_Java_thread() const { return true; }
1132 virtual bool can_call_java() const { return true; }
1133
1134 // Thread chain operations
1135 JavaThread* next() const { return _next; }
1136 void set_next(JavaThread* p) { _next = p; }
1137
1138 // Thread oop. threadObj() can be NULL for initial JavaThread
1139 // (or for threads attached via JNI)
1140 oop threadObj() const { return _threadObj; }
1141 void set_threadObj(oop p) { _threadObj = p; }
1142
1143 ThreadPriority java_priority() const; // Read from threadObj()
1144
1145 // Prepare thread and add to priority queue. If a priority is
1146 // not specified, use the priority of the thread object. Threads_lock
1147 // must be held while this function is called.
1148 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1149
1150 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
1151 address saved_exception_pc() { return _saved_exception_pc; }
1152
1153
1154 ThreadFunction entry_point() const { return _entry_point; }
1155
1156 // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1157 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1158
1159 // Last frame anchor routines
1160
1161 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
1162
1163 // last_Java_sp
1164 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
1165 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
1166
1167 // last_Java_pc
1168
1169 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
1170
1171 // Safepoint support
1172 #if !(defined(PPC64) || defined(AARCH64))
1173 JavaThreadState thread_state() const { return _thread_state; }
1174 void set_thread_state(JavaThreadState s) { _thread_state = s; }
1175 #else
1176 // Use membars when accessing volatile _thread_state. See
1177 // Threads::create_vm() for size checks.
1178 inline JavaThreadState thread_state() const;
1179 inline void set_thread_state(JavaThreadState s);
1180 #endif
1181 ThreadSafepointState *safepoint_state() const { return _safepoint_state; }
1182 void set_safepoint_state(ThreadSafepointState *state) { _safepoint_state = state; }
1183 bool is_at_poll_safepoint() { return _safepoint_state->is_at_poll_safepoint(); }
1184
1185 // JavaThread termination and lifecycle support:
1186 void smr_delete();
1187 bool on_thread_list() const { return _on_thread_list; }
1188 void set_on_thread_list() { _on_thread_list = true; }
1189
1190 // thread has called JavaThread::exit() or is terminated
1191 bool is_exiting() const;
1192 // thread is terminated (no longer on the threads list); we compare
1193 // against the two non-terminated values so that a freed JavaThread
1194 // will also be considered terminated.
1195 bool check_is_terminated(TerminatedTypes l_terminated) const {
1196 return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1197 }
1198 bool is_terminated() const;
1199 void set_terminated(TerminatedTypes t);
1200 // special for Threads::remove() which is static:
1201 void set_terminated_value();
1202 void block_if_vm_exited();
1203
1204 bool doing_unsafe_access() { return _doing_unsafe_access; }
1205 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
1206
1207 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
1208 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1209
1210 inline void set_polling_page(void* poll_value);
1211 inline volatile void* get_polling_page();
1212
1213 private:
1214 // Support for thread handshake operations
1215 HandshakeState _handshake;
1216 public:
1217 void set_handshake_operation(HandshakeOperation* op) {
1218 _handshake.set_operation(this, op);
1219 }
1220
1221 bool has_handshake() const {
1222 return _handshake.has_operation();
1223 }
1224
1225 void cancel_handshake() {
1226 _handshake.cancel(this);
1227 }
1228
1229 void handshake_process_by_self() {
1230 _handshake.process_by_self(this);
1231 }
1232
1233 void handshake_process_by_vmthread() {
1234 _handshake.process_by_vmthread(this);
1235 }
1236
1237 // Suspend/resume support for JavaThread
1238 private:
1239 inline void set_ext_suspended();
1240 inline void clear_ext_suspended();
1241
1242 public:
1243 void java_suspend();
1244 void java_resume();
1245 int java_suspend_self();
1246
1247 void check_and_wait_while_suspended() {
1248 assert(JavaThread::current() == this, "sanity check");
1249
1250 bool do_self_suspend;
1251 do {
1252 // were we externally suspended while we were waiting?
1253 do_self_suspend = handle_special_suspend_equivalent_condition();
1254 if (do_self_suspend) {
1255 // don't surprise the thread that suspended us by returning
1256 java_suspend_self();
1257 set_suspend_equivalent();
1258 }
1259 } while (do_self_suspend);
1260 }
1261 static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1262 // Check for async exception in addition to safepoint and suspend request.
1263 static void check_special_condition_for_native_trans(JavaThread *thread);
1264
1265 // Same as check_special_condition_for_native_trans but finishes the
1266 // transition into thread_in_Java mode so that it can potentially
1267 // block.
1268 static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1269
1270 bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1271 bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1272 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1273 // Warning: is_ext_suspend_completed() may temporarily drop the
1274 // SR_lock to allow the thread to reach a stable thread state if
1275 // it is currently in a transient thread state.
1276 return is_ext_suspend_completed(false /* !called_by_wait */,
1277 SuspendRetryDelay, bits);
1278 }
1279
1280 // We cannot allow wait_for_ext_suspend_completion() to run forever or
1281 // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1282 // passed as the count and delay parameters. Experiments with specific
1283 // calls to wait_for_ext_suspend_completion() can be done by passing
1284 // other values in the code. Experiments with all calls can be done
1285 // via the appropriate -XX options.
1286 bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1287
1288 // test for suspend - most (all?) of these should go away
1289 bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits);
1290
1291 inline void set_external_suspend();
1292 inline void clear_external_suspend();
1293
1294 inline void set_deopt_suspend();
1295 inline void clear_deopt_suspend();
1296 bool is_deopt_suspend() { return (_suspend_flags & _deopt_suspend) != 0; }
1297
1298 bool is_external_suspend() const {
1299 return (_suspend_flags & _external_suspend) != 0;
1300 }
1301 // Whenever a thread transitions from native to vm/java it must suspend
1302 // if external|deopt suspend is present.
1303 bool is_suspend_after_native() const {
1304 return (_suspend_flags & (_external_suspend | _deopt_suspend)) != 0;
1305 }
1306
1307 // external suspend request is completed
1308 bool is_ext_suspended() const {
1309 return (_suspend_flags & _ext_suspended) != 0;
1310 }
1311
1312 bool is_external_suspend_with_lock() const {
1313 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1314 return is_external_suspend();
1315 }
1316
1317 // Special method to handle a pending external suspend request
1318 // when a suspend equivalent condition lifts.
1319 bool handle_special_suspend_equivalent_condition() {
1320 assert(is_suspend_equivalent(),
1321 "should only be called in a suspend equivalence condition");
1322 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1323 bool ret = is_external_suspend();
1324 if (!ret) {
1325 // not about to self-suspend so clear suspend equivalence
1326 clear_suspend_equivalent();
1327 }
1328 // implied else:
1329 // We have a pending external suspend request so we leave the
1330 // suspend_equivalent flag set until java_suspend_self() sets
1331 // the ext_suspended flag and clears the suspend_equivalent
1332 // flag. This insures that wait_for_ext_suspend_completion()
1333 // will return consistent values.
1334 return ret;
1335 }
1336
1337 // utility methods to see if we are doing some kind of suspension
1338 bool is_being_ext_suspended() const {
1339 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1340 return is_ext_suspended() || is_external_suspend();
1341 }
1342
1343 bool is_suspend_equivalent() const { return _suspend_equivalent; }
1344
1345 void set_suspend_equivalent() { _suspend_equivalent = true; }
1346 void clear_suspend_equivalent() { _suspend_equivalent = false; }
1347
1348 // Thread.stop support
1349 void send_thread_stop(oop throwable);
1350 AsyncRequests clear_special_runtime_exit_condition() {
1351 AsyncRequests x = _special_runtime_exit_condition;
1352 _special_runtime_exit_condition = _no_async_condition;
1353 return x;
1354 }
1355
1356 // Are any async conditions present?
1357 bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1358
1359 void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1360
1361 // these next two are also used for self-suspension and async exception support
1362 void handle_special_runtime_exit_condition(bool check_asyncs = true);
1363
1364 // Return true if JavaThread has an asynchronous condition or
1365 // if external suspension is requested.
1366 bool has_special_runtime_exit_condition() {
1367 // Because we don't use is_external_suspend_with_lock
1368 // it is possible that we won't see an asynchronous external suspend
1369 // request that has just gotten started, i.e., SR_lock grabbed but
1370 // _external_suspend field change either not made yet or not visible
1371 // yet. However, this is okay because the request is asynchronous and
1372 // we will see the new flag value the next time through. It's also
1373 // possible that the external suspend request is dropped after
1374 // we have checked is_external_suspend(), we will recheck its value
1375 // under SR_lock in java_suspend_self().
1376 return (_special_runtime_exit_condition != _no_async_condition) ||
1377 is_external_suspend() || is_trace_suspend();
1378 }
1379
1380 void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; }
1381
1382 inline void set_pending_async_exception(oop e);
1383
1384 // Fast-locking support
1385 bool is_lock_owned(address adr) const;
1386
1387 // Accessors for vframe array top
1388 // The linked list of vframe arrays are sorted on sp. This means when we
1389 // unpack the head must contain the vframe array to unpack.
1390 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1391 vframeArray* vframe_array_head() const { return _vframe_array_head; }
1392
1393 // Side structure for deferring update of java frame locals until deopt occurs
1394 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1395 void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1396
1397 // These only really exist to make debugging deopt problems simpler
1398
1399 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1400 vframeArray* vframe_array_last() const { return _vframe_array_last; }
1401
1402 // The special resourceMark used during deoptimization
1403
1404 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
1405 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
1406
1407 intptr_t* must_deopt_id() { return _must_deopt_id; }
1408 void set_must_deopt_id(intptr_t* id) { _must_deopt_id = id; }
1409 void clear_must_deopt_id() { _must_deopt_id = NULL; }
1410
1411 void set_deopt_compiled_method(CompiledMethod* nm) { _deopt_nmethod = nm; }
1412 CompiledMethod* deopt_compiled_method() { return _deopt_nmethod; }
1413
1414 Method* callee_target() const { return _callee_target; }
1415 void set_callee_target (Method* x) { _callee_target = x; }
1416
1417 // Oop results of vm runtime calls
1418 oop vm_result() const { return _vm_result; }
1419 void set_vm_result (oop x) { _vm_result = x; }
1420
1421 Metadata* vm_result_2() const { return _vm_result_2; }
1422 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
1423
1424 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
1425 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
1426
1427 #if INCLUDE_JVMCI
1428 int pending_deoptimization() const { return _pending_deoptimization; }
1429 long pending_failed_speculation() const { return _pending_failed_speculation; }
1430 bool adjusting_comp_level() const { return _adjusting_comp_level; }
1431 void set_adjusting_comp_level(bool b) { _adjusting_comp_level = b; }
1432 bool has_pending_monitorenter() const { return _pending_monitorenter; }
1433 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
1434 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
1435 void set_pending_failed_speculation(long failed_speculation) { _pending_failed_speculation = failed_speculation; }
1436 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1437 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1438 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1439 #endif // INCLUDE_JVMCI
1440
1441 // Exception handling for compiled methods
1442 oop exception_oop() const { return _exception_oop; }
1443 address exception_pc() const { return _exception_pc; }
1444 address exception_handler_pc() const { return _exception_handler_pc; }
1445 bool is_method_handle_return() const { return _is_method_handle_return == 1; }
1446
1447 void set_exception_oop(oop o) { (void)const_cast<oop&>(_exception_oop = o); }
1448 void set_exception_pc(address a) { _exception_pc = a; }
1449 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
1450 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
1451
1452 void clear_exception_oop_and_pc() {
1453 set_exception_oop(NULL);
1454 set_exception_pc(NULL);
1455 }
1456
1457 // Stack overflow support
1458 //
1459 // (small addresses)
1460 //
1461 // -- <-- stack_end() ---
1462 // | |
1463 // | red pages |
1464 // | |
1465 // -- <-- stack_red_zone_base() |
1466 // | |
1467 // | guard
1468 // | yellow pages zone
1469 // | |
1470 // | |
1471 // -- <-- stack_yellow_zone_base() |
1472 // | |
1473 // | |
1474 // | reserved pages |
1475 // | |
1476 // -- <-- stack_reserved_zone_base() --- ---
1477 // /|\ shadow <-- stack_overflow_limit() (somewhere in here)
1478 // | zone
1479 // \|/ size
1480 // some untouched memory ---
1481 //
1482 //
1483 // --
1484 // |
1485 // | shadow zone
1486 // |
1487 // --
1488 // x frame n
1489 // --
1490 // x frame n-1
1491 // x
1492 // --
1493 // ...
1494 //
1495 // --
1496 // x frame 0
1497 // -- <-- stack_base()
1498 //
1499 // (large addresses)
1500 //
1501
1502 private:
1503 // These values are derived from flags StackRedPages, StackYellowPages,
1504 // StackReservedPages and StackShadowPages. The zone size is determined
1505 // ergonomically if page_size > 4K.
1506 static size_t _stack_red_zone_size;
1507 static size_t _stack_yellow_zone_size;
1508 static size_t _stack_reserved_zone_size;
1509 static size_t _stack_shadow_zone_size;
1510 public:
1511 inline size_t stack_available(address cur_sp);
1512
1513 static size_t stack_red_zone_size() {
1514 assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1515 return _stack_red_zone_size;
1516 }
1517 static void set_stack_red_zone_size(size_t s) {
1518 assert(is_aligned(s, os::vm_page_size()),
1519 "We can not protect if the red zone size is not page aligned.");
1520 assert(_stack_red_zone_size == 0, "This should be called only once.");
1521 _stack_red_zone_size = s;
1522 }
1523 address stack_red_zone_base() {
1524 return (address)(stack_end() + stack_red_zone_size());
1525 }
1526 bool in_stack_red_zone(address a) {
1527 return a <= stack_red_zone_base() && a >= stack_end();
1528 }
1529
1530 static size_t stack_yellow_zone_size() {
1531 assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1532 return _stack_yellow_zone_size;
1533 }
1534 static void set_stack_yellow_zone_size(size_t s) {
1535 assert(is_aligned(s, os::vm_page_size()),
1536 "We can not protect if the yellow zone size is not page aligned.");
1537 assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1538 _stack_yellow_zone_size = s;
1539 }
1540
1541 static size_t stack_reserved_zone_size() {
1542 // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1543 return _stack_reserved_zone_size;
1544 }
1545 static void set_stack_reserved_zone_size(size_t s) {
1546 assert(is_aligned(s, os::vm_page_size()),
1547 "We can not protect if the reserved zone size is not page aligned.");
1548 assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1549 _stack_reserved_zone_size = s;
1550 }
1551 address stack_reserved_zone_base() {
1552 return (address)(stack_end() +
1553 (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1554 }
1555 bool in_stack_reserved_zone(address a) {
1556 return (a <= stack_reserved_zone_base()) &&
1557 (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1558 }
1559
1560 static size_t stack_yellow_reserved_zone_size() {
1561 return _stack_yellow_zone_size + _stack_reserved_zone_size;
1562 }
1563 bool in_stack_yellow_reserved_zone(address a) {
1564 return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1565 }
1566
1567 // Size of red + yellow + reserved zones.
1568 static size_t stack_guard_zone_size() {
1569 return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1570 }
1571
1572 static size_t stack_shadow_zone_size() {
1573 assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1574 return _stack_shadow_zone_size;
1575 }
1576 static void set_stack_shadow_zone_size(size_t s) {
1577 // The shadow area is not allocated or protected, so
1578 // it needs not be page aligned.
1579 // But the stack bang currently assumes that it is a
1580 // multiple of page size. This guarantees that the bang
1581 // loop touches all pages in the shadow zone.
1582 // This can be guaranteed differently, as well. E.g., if
1583 // the page size is a multiple of 4K, banging in 4K steps
1584 // suffices to touch all pages. (Some pages are banged
1585 // several times, though.)
1586 assert(is_aligned(s, os::vm_page_size()),
1587 "Stack bang assumes multiple of page size.");
1588 assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1589 _stack_shadow_zone_size = s;
1590 }
1591
1592 void create_stack_guard_pages();
1593 void remove_stack_guard_pages();
1594
1595 void enable_stack_reserved_zone();
1596 void disable_stack_reserved_zone();
1597 void enable_stack_yellow_reserved_zone();
1598 void disable_stack_yellow_reserved_zone();
1599 void enable_stack_red_zone();
1600 void disable_stack_red_zone();
1601
1602 inline bool stack_guard_zone_unused();
1603 inline bool stack_yellow_reserved_zone_disabled();
1604 inline bool stack_reserved_zone_disabled();
1605 inline bool stack_guards_enabled();
1606
1607 address reserved_stack_activation() const { return _reserved_stack_activation; }
1608 void set_reserved_stack_activation(address addr) {
1609 assert(_reserved_stack_activation == stack_base()
1610 || _reserved_stack_activation == NULL
1611 || addr == stack_base(), "Must not be set twice");
1612 _reserved_stack_activation = addr;
1613 }
1614
1615 // Attempt to reguard the stack after a stack overflow may have occurred.
1616 // Returns true if (a) guard pages are not needed on this thread, (b) the
1617 // pages are already guarded, or (c) the pages were successfully reguarded.
1618 // Returns false if there is not enough stack space to reguard the pages, in
1619 // which case the caller should unwind a frame and try again. The argument
1620 // should be the caller's (approximate) sp.
1621 bool reguard_stack(address cur_sp);
1622 // Similar to above but see if current stackpoint is out of the guard area
1623 // and reguard if possible.
1624 bool reguard_stack(void);
1625
1626 address stack_overflow_limit() { return _stack_overflow_limit; }
1627 void set_stack_overflow_limit() {
1628 _stack_overflow_limit =
1629 stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1630 }
1631
1632 // Misc. accessors/mutators
1633 void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; }
1634 void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; }
1635 bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; }
1636
1637 #ifndef PRODUCT
1638 void record_jump(address target, address instr, const char* file, int line);
1639 #endif // PRODUCT
1640
1641 // For assembly stub generation
1642 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
1643 #ifndef PRODUCT
1644 static ByteSize jmp_ring_index_offset() { return byte_offset_of(JavaThread, _jmp_ring_index); }
1645 static ByteSize jmp_ring_offset() { return byte_offset_of(JavaThread, _jmp_ring); }
1646 #endif // PRODUCT
1647 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
1648 static ByteSize pending_jni_exception_check_fn_offset() {
1649 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1650 }
1651 static ByteSize last_Java_sp_offset() {
1652 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1653 }
1654 static ByteSize last_Java_pc_offset() {
1655 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1656 }
1657 static ByteSize frame_anchor_offset() {
1658 return byte_offset_of(JavaThread, _anchor);
1659 }
1660 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
1661 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); }
1662 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); }
1663 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
1664 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
1665 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
1666 #if INCLUDE_JVMCI
1667 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1668 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
1669 static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1670 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1671 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1672 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
1673 #endif // INCLUDE_JVMCI
1674 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
1675 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
1676 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
1677 static ByteSize stack_overflow_limit_offset() { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1678 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1679 static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state); }
1680 static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1681 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
1682
1683 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1684 static ByteSize should_post_on_exceptions_flag_offset() {
1685 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1686 }
1687
1688 // Returns the jni environment for this thread
1689 JNIEnv* jni_environment() { return &_jni_environment; }
1690
1691 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1692 JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1693 // Only return NULL if thread is off the thread list; starting to
1694 // exit should not return NULL.
1695 if (thread_from_jni_env->is_terminated()) {
1696 thread_from_jni_env->block_if_vm_exited();
1697 return NULL;
1698 } else {
1699 return thread_from_jni_env;
1700 }
1701 }
1702
1703 // JNI critical regions. These can nest.
1704 bool in_critical() { return _jni_active_critical > 0; }
1705 bool in_last_critical() { return _jni_active_critical == 1; }
1706 void enter_critical() {
1707 assert(Thread::current() == this ||
1708 (Thread::current()->is_VM_thread() &&
1709 SafepointSynchronize::is_synchronizing()),
1710 "this must be current thread or synchronizing");
1711 _jni_active_critical++;
1712 }
1713 void exit_critical() {
1714 assert(Thread::current() == this, "this must be current thread");
1715 _jni_active_critical--;
1716 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1717 }
1718
1719 // Checked JNI: is the programmer required to check for exceptions, if so specify
1720 // which function name. Returning to a Java frame should implicitly clear the
1721 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1722 // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1723 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1724 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1725 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1726 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1727 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1728
1729 // For deadlock detection
1730 int depth_first_number() { return _depth_first_number; }
1731 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1732
1733 private:
1734 void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1735
1736 public:
1737 MonitorChunk* monitor_chunks() const { return _monitor_chunks; }
1738 void add_monitor_chunk(MonitorChunk* chunk);
1739 void remove_monitor_chunk(MonitorChunk* chunk);
1740 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
1741 void inc_in_deopt_handler() { _in_deopt_handler++; }
1742 void dec_in_deopt_handler() {
1743 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1744 if (_in_deopt_handler > 0) { // robustness
1745 _in_deopt_handler--;
1746 }
1747 }
1748
1749 private:
1750 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1751
1752 public:
1753
1754 // Frame iteration; calls the function f for all frames on the stack
1755 void frames_do(void f(frame*, const RegisterMap*));
1756
1757 // Memory operations
1758 void oops_do(OopClosure* f, CodeBlobClosure* cf);
1759
1760 // Sweeper operations
1761 virtual void nmethods_do(CodeBlobClosure* cf);
1762
1763 // RedefineClasses Support
1764 void metadata_do(void f(Metadata*));
1765
1766 // Misc. operations
1767 char* name() const { return (char*)get_thread_name(); }
1768 void print_on(outputStream* st, bool print_extended_info) const;
1769 void print_on(outputStream* st) const { print_on(st, false); }
1770 void print_value();
1771 void print_thread_state_on(outputStream*) const PRODUCT_RETURN;
1772 void print_thread_state() const PRODUCT_RETURN;
1773 void print_on_error(outputStream* st, char* buf, int buflen) const;
1774 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1775 void verify();
1776 const char* get_thread_name() const;
1777 private:
1778 // factor out low-level mechanics for use in both normal and error cases
1779 const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1780 public:
1781 const char* get_threadgroup_name() const;
1782 const char* get_parent_name() const;
1783
1784 // Accessing frames
1785 frame last_frame() {
1786 _anchor.make_walkable(this);
1787 return pd_last_frame();
1788 }
1789 javaVFrame* last_java_vframe(RegisterMap* reg_map);
1790
1791 // Returns method at 'depth' java or native frames down the stack
1792 // Used for security checks
1793 Klass* security_get_caller_class(int depth);
1794
1795 // Print stack trace in external format
1796 void print_stack_on(outputStream* st);
1797 void print_stack() { print_stack_on(tty); }
1798
1799 // Print stack traces in various internal formats
1800 void trace_stack() PRODUCT_RETURN;
1801 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1802 void trace_frames() PRODUCT_RETURN;
1803 void trace_oops() PRODUCT_RETURN;
1804
1805 // Print an annotated view of the stack frames
1806 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1807 void validate_frame_layout() {
1808 print_frame_layout(0, true);
1809 }
1810
1811 // Returns the number of stack frames on the stack
1812 int depth() const;
1813
1814 // Function for testing deoptimization
1815 void deoptimize();
1816 void make_zombies();
1817
1818 void deoptimized_wrt_marked_nmethods();
1819
1820 public:
1821 // Returns the running thread as a JavaThread
1822 static inline JavaThread* current();
1823
1824 // Returns the active Java thread. Do not use this if you know you are calling
1825 // from a JavaThread, as it's slower than JavaThread::current. If called from
1826 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1827 // operation. You may not want that either.
1828 static JavaThread* active();
1829
1830 inline CompilerThread* as_CompilerThread();
1831
1832 public:
1833 virtual void run();
1834 void thread_main_inner();
1835
1836 private:
1837 // PRIVILEGED STACK
1838 PrivilegedElement* _privileged_stack_top;
1839 GrowableArray<oop>* _array_for_gc;
1840 public:
1841
1842 // Returns the privileged_stack information.
1843 PrivilegedElement* privileged_stack_top() const { return _privileged_stack_top; }
1844 void set_privileged_stack_top(PrivilegedElement *e) { _privileged_stack_top = e; }
1845 void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1846
1847 public:
1848 // Thread local information maintained by JVMTI.
1849 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1850 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1851 // getter is used to get this JavaThread's JvmtiThreadState if it has
1852 // one which means NULL can be returned. JvmtiThreadState::state_for()
1853 // is used to get the specified JavaThread's JvmtiThreadState if it has
1854 // one or it allocates a new JvmtiThreadState for the JavaThread and
1855 // returns it. JvmtiThreadState::state_for() will return NULL only if
1856 // the specified JavaThread is exiting.
1857 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1858 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1859 void set_jvmti_get_loaded_classes_closure(JvmtiGetLoadedClassesClosure* value) { _jvmti_get_loaded_classes_closure = value; }
1860 JvmtiGetLoadedClassesClosure* get_jvmti_get_loaded_classes_closure() const { return _jvmti_get_loaded_classes_closure; }
1861
1862 // JVMTI PopFrame support
1863 // Setting and clearing popframe_condition
1864 // All of these enumerated values are bits. popframe_pending
1865 // indicates that a PopFrame() has been requested and not yet been
1866 // completed. popframe_processing indicates that that PopFrame() is in
1867 // the process of being completed. popframe_force_deopt_reexecution_bit
1868 // indicates that special handling is required when returning to a
1869 // deoptimized caller.
1870 enum PopCondition {
1871 popframe_inactive = 0x00,
1872 popframe_pending_bit = 0x01,
1873 popframe_processing_bit = 0x02,
1874 popframe_force_deopt_reexecution_bit = 0x04
1875 };
1876 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1877 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1878 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1879 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1880 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1881 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1882 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1883 void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1884 #ifdef CC_INTERP
1885 bool pop_frame_pending(void) { return ((_popframe_condition & popframe_pending_bit) != 0); }
1886 void clr_pop_frame_pending(void) { _popframe_condition = popframe_inactive; }
1887 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1888 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
1889 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
1890 #endif
1891
1892 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
1893 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
1894 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
1895
1896 private:
1897 // Saved incoming arguments to popped frame.
1898 // Used only when popped interpreted frame returns to deoptimized frame.
1899 void* _popframe_preserved_args;
1900 int _popframe_preserved_args_size;
1901
1902 public:
1903 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
1904 void* popframe_preserved_args();
1905 ByteSize popframe_preserved_args_size();
1906 WordSize popframe_preserved_args_size_in_words();
1907 void popframe_free_preserved_args();
1908
1909
1910 private:
1911 JvmtiThreadState *_jvmti_thread_state;
1912 JvmtiGetLoadedClassesClosure* _jvmti_get_loaded_classes_closure;
1913
1914 // Used by the interpreter in fullspeed mode for frame pop, method
1915 // entry, method exit and single stepping support. This field is
1916 // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
1917 // It can be set to zero asynchronously (i.e., without a VM operation
1918 // or a lock) so we have to be very careful.
1919 int _interp_only_mode;
1920
1921 public:
1922 // used by the interpreter for fullspeed debugging support (see above)
1923 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1924 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
1925 int get_interp_only_mode() { return _interp_only_mode; }
1926 void increment_interp_only_mode() { ++_interp_only_mode; }
1927 void decrement_interp_only_mode() { --_interp_only_mode; }
1928
1929 // support for cached flag that indicates whether exceptions need to be posted for this thread
1930 // if this is false, we can avoid deoptimizing when events are thrown
1931 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1932 private:
1933 int _should_post_on_exceptions_flag;
1934
1935 public:
1936 int should_post_on_exceptions_flag() { return _should_post_on_exceptions_flag; }
1937 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
1938
1939 private:
1940 ThreadStatistics *_thread_stat;
1941
1942 public:
1943 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
1944
1945 // Return a blocker object for which this thread is blocked parking.
1946 oop current_park_blocker();
1947
1948 private:
1949 static size_t _stack_size_at_create;
1950
1951 public:
1952 static inline size_t stack_size_at_create(void) {
1953 return _stack_size_at_create;
1954 }
1955 static inline void set_stack_size_at_create(size_t value) {
1956 _stack_size_at_create = value;
1957 }
1958
1959 // Machine dependent stuff
1960 #include OS_CPU_HEADER(thread)
1961
1962 public:
1963 void set_blocked_on_compilation(bool value) {
1964 _blocked_on_compilation = value;
1965 }
1966
1967 bool blocked_on_compilation() {
1968 return _blocked_on_compilation;
1969 }
1970 protected:
1971 bool _blocked_on_compilation;
1972
1973
1974 // JSR166 per-thread parker
1975 private:
1976 Parker* _parker;
1977 public:
1978 Parker* parker() { return _parker; }
1979
1980 // Biased locking support
1981 private:
1982 GrowableArray<MonitorInfo*>* _cached_monitor_info;
1983 public:
1984 GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
1985 void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
1986
1987 // clearing/querying jni attach status
1988 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
1989 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
1990 inline void set_done_attaching_via_jni();
1991 };
1992
1993 // Inline implementation of JavaThread::current
1994 inline JavaThread* JavaThread::current() {
1995 Thread* thread = Thread::current();
1996 assert(thread->is_Java_thread(), "just checking");
1997 return (JavaThread*)thread;
1998 }
1999
2000 inline CompilerThread* JavaThread::as_CompilerThread() {
2001 assert(is_Compiler_thread(), "just checking");
2002 return (CompilerThread*)this;
2003 }
2004
2005 // Dedicated thread to sweep the code cache
2006 class CodeCacheSweeperThread : public JavaThread {
2007 CompiledMethod* _scanned_compiled_method; // nmethod being scanned by the sweeper
2008 public:
2009 CodeCacheSweeperThread();
2010 // Track the nmethod currently being scanned by the sweeper
2011 void set_scanned_compiled_method(CompiledMethod* cm) {
2012 assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value");
2013 _scanned_compiled_method = cm;
2014 }
2015
2016 // Hide sweeper thread from external view.
2017 bool is_hidden_from_external_view() const { return true; }
2018
2019 bool is_Code_cache_sweeper_thread() const { return true; }
2020
2021 // Prevent GC from unloading _scanned_compiled_method
2022 void oops_do(OopClosure* f, CodeBlobClosure* cf);
2023 void nmethods_do(CodeBlobClosure* cf);
2024 };
2025
2026 // A thread used for Compilation.
2027 class CompilerThread : public JavaThread {
2028 friend class VMStructs;
2029 private:
2030 CompilerCounters* _counters;
2031
2032 ciEnv* _env;
2033 CompileLog* _log;
2034 CompileTask* volatile _task; // print_threads_compiling can read this concurrently.
2035 CompileQueue* _queue;
2036 BufferBlob* _buffer_blob;
2037
2038 AbstractCompiler* _compiler;
2039 TimeStamp _idle_time;
2040
2041 public:
2042
2043 static CompilerThread* current();
2044
2045 CompilerThread(CompileQueue* queue, CompilerCounters* counters);
2046 ~CompilerThread();
2047
2048 bool is_Compiler_thread() const { return true; }
2049
2050 virtual bool can_call_java() const;
2051
2052 // Hide native compiler threads from external view.
2053 bool is_hidden_from_external_view() const { return !can_call_java(); }
2054
2055 void set_compiler(AbstractCompiler* c) { _compiler = c; }
2056 AbstractCompiler* compiler() const { return _compiler; }
2057
2058 CompileQueue* queue() const { return _queue; }
2059 CompilerCounters* counters() const { return _counters; }
2060
2061 // Get/set the thread's compilation environment.
2062 ciEnv* env() { return _env; }
2063 void set_env(ciEnv* env) { _env = env; }
2064
2065 BufferBlob* get_buffer_blob() const { return _buffer_blob; }
2066 void set_buffer_blob(BufferBlob* b) { _buffer_blob = b; }
2067
2068 // Get/set the thread's logging information
2069 CompileLog* log() { return _log; }
2070 void init_log(CompileLog* log) {
2071 // Set once, for good.
2072 assert(_log == NULL, "set only once");
2073 _log = log;
2074 }
2075
2076 void start_idle_timer() { _idle_time.update(); }
2077 jlong idle_time_millis() {
2078 return TimeHelper::counter_to_millis(_idle_time.ticks_since_update());
2079 }
2080
2081 #ifndef PRODUCT
2082 private:
2083 IdealGraphPrinter *_ideal_graph_printer;
2084 public:
2085 IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; }
2086 void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2087 #endif
2088
2089 // Get/set the thread's current task
2090 CompileTask* task() { return _task; }
2091 void set_task(CompileTask* task) { _task = task; }
2092 };
2093
2094 inline CompilerThread* CompilerThread::current() {
2095 return JavaThread::current()->as_CompilerThread();
2096 }
2097
2098 // The active thread queue. It also keeps track of the current used
2099 // thread priorities.
2100 class Threads: AllStatic {
2101 friend class VMStructs;
2102 private:
2103 static JavaThread* _thread_list;
2104 static int _number_of_threads;
2105 static int _number_of_non_daemon_threads;
2106 static int _return_code;
2107 static int _thread_claim_parity;
2108 #ifdef ASSERT
2109 static bool _vm_complete;
2110 #endif
2111
2112 static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2113 static void initialize_jsr292_core_classes(TRAPS);
2114
2115 public:
2116 // Thread management
2117 // force_daemon is a concession to JNI, where we may need to add a
2118 // thread to the thread list before allocating its thread object
2119 static void add(JavaThread* p, bool force_daemon = false);
2120 static void remove(JavaThread* p);
2121 static void non_java_threads_do(ThreadClosure* tc);
2122 static void java_threads_do(ThreadClosure* tc);
2123 static void java_threads_and_vm_thread_do(ThreadClosure* tc);
2124 static void threads_do(ThreadClosure* tc);
2125 static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
2126
2127 // Initializes the vm and creates the vm thread
2128 static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
2129 static void convert_vm_init_libraries_to_agents();
2130 static void create_vm_init_libraries();
2131 static void create_vm_init_agents();
2132 static void shutdown_vm_agents();
2133 static bool destroy_vm();
2134 // Supported VM versions via JNI
2135 // Includes JNI_VERSION_1_1
2136 static jboolean is_supported_jni_version_including_1_1(jint version);
2137 // Does not include JNI_VERSION_1_1
2138 static jboolean is_supported_jni_version(jint version);
2139
2140 // The "thread claim parity" provides a way for threads to be claimed
2141 // by parallel worker tasks.
2142 //
2143 // Each thread contains a a "parity" field. A task will claim the
2144 // thread only if its parity field is the same as the global parity,
2145 // which is updated by calling change_thread_claim_parity().
2146 //
2147 // For this to work change_thread_claim_parity() needs to be called
2148 // exactly once in sequential code before starting parallel tasks
2149 // that should claim threads.
2150 //
2151 // New threads get their parity set to 0 and change_thread_claim_parity()
2152 // never set the global parity to 0.
2153 static int thread_claim_parity() { return _thread_claim_parity; }
2154 static void change_thread_claim_parity();
2155 static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
2156
2157 // Apply "f->do_oop" to all root oops in all threads.
2158 // This version may only be called by sequential code.
2159 static void oops_do(OopClosure* f, CodeBlobClosure* cf);
2160 // This version may be called by sequential or parallel code.
2161 static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
2162
2163 // Apply "f->do_oop" to roots in all threads that
2164 // are part of compiled frames
2165 static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf);
2166
2167 static void convert_hcode_pointers();
2168 static void restore_hcode_pointers();
2169
2170 // Sweeper
2171 static void nmethods_do(CodeBlobClosure* cf);
2172
2173 // RedefineClasses support
2174 static void metadata_do(void f(Metadata*));
2175 static void metadata_handles_do(void f(Metadata*));
2176
2177 #ifdef ASSERT
2178 static bool is_vm_complete() { return _vm_complete; }
2179 #endif
2180
2181 // Verification
2182 static void verify();
2183 static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks, bool print_extended_info);
2184 static void print(bool print_stacks, bool internal_format) {
2185 // this function is only used by debug.cpp
2186 print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */, false /* simple format */);
2187 }
2188 static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2189 static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
2190 int buflen, bool* found_current);
2191 static void print_threads_compiling(outputStream* st, char* buf, int buflen);
2192
2193 // Get Java threads that are waiting to enter a monitor.
2194 static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
2195 int count, address monitor);
2196
2197 // Get owning Java thread from the monitor's owner field.
2198 static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
2199 address owner);
2200
2201 // Number of threads on the active threads list
2202 static int number_of_threads() { return _number_of_threads; }
2203 // Number of non-daemon threads on the active threads list
2204 static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; }
2205
2206 // Deoptimizes all frames tied to marked nmethods
2207 static void deoptimized_wrt_marked_nmethods();
2208 };
2209
2210
2211 // Thread iterator
2212 class ThreadClosure: public StackObj {
2213 public:
2214 virtual void do_thread(Thread* thread) = 0;
2215 };
2216
2217 class SignalHandlerMark: public StackObj {
2218 private:
2219 Thread* _thread;
2220 public:
2221 SignalHandlerMark(Thread* t) {
2222 _thread = t;
2223 if (_thread) _thread->enter_signal_handler();
2224 }
2225 ~SignalHandlerMark() {
2226 if (_thread) _thread->leave_signal_handler();
2227 _thread = NULL;
2228 }
2229 };
2230
2231
2232 #endif // SHARE_VM_RUNTIME_THREAD_HPP