1 /*
2 * Copyright (c) 1997, 2017, 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/threadLocalAllocBuffer.hpp"
30 #include "memory/allocation.hpp"
31 #include "oops/oop.hpp"
32 #include "prims/jvmtiExport.hpp"
33 #include "runtime/frame.hpp"
34 #include "runtime/javaFrameAnchor.hpp"
35 #include "runtime/jniHandles.hpp"
36 #include "runtime/mutexLocker.hpp"
37 #include "runtime/os.hpp"
38 #include "runtime/osThread.hpp"
39 #include "runtime/park.hpp"
40 #include "runtime/safepoint.hpp"
41 #include "runtime/stubRoutines.hpp"
42 #include "runtime/threadLocalStorage.hpp"
43 #include "runtime/thread_ext.hpp"
44 #include "runtime/unhandledOops.hpp"
45 #include "trace/traceBackend.hpp"
46 #include "trace/traceMacros.hpp"
47 #include "utilities/align.hpp"
48 #include "utilities/exceptions.hpp"
49 #include "utilities/macros.hpp"
50 #if INCLUDE_ALL_GCS
51 #include "gc/g1/dirtyCardQueue.hpp"
52 #include "gc/g1/satbMarkQueue.hpp"
53 #endif // INCLUDE_ALL_GCS
54 #ifdef ZERO
55 # include "stack_zero.hpp"
56 #endif
57
58 class ThreadSafepointState;
59 class ThreadsList;
60 class NestedThreadsList;
61
62 class JvmtiThreadState;
63 class JvmtiGetLoadedClassesClosure;
64 class ThreadStatistics;
65 class ConcurrentLocksDump;
66 class ParkEvent;
67 class Parker;
68
69 class ciEnv;
70 class CompileThread;
71 class CompileLog;
72 class CompileTask;
73 class CompileQueue;
74 class CompilerCounters;
75 class vframeArray;
76
77 class DeoptResourceMark;
78 class jvmtiDeferredLocalVariableSet;
79
80 class GCTaskQueue;
81 class ThreadClosure;
82 class IdealGraphPrinter;
83
84 class Metadata;
85 template <class T, MEMFLAGS F> class ChunkedList;
86 typedef ChunkedList<Metadata*, mtInternal> MetadataOnStackBuffer;
87
88 DEBUG_ONLY(class ResourceMark;)
89
90 class WorkerThread;
91
92 // Class hierarchy
93 // - Thread
94 // - NamedThread
95 // - VMThread
96 // - ConcurrentGCThread
97 // - WorkerThread
98 // - GangWorker
99 // - GCTaskThread
100 // - JavaThread
101 // - various subclasses eg CompilerThread, ServiceThread
102 // - WatcherThread
103
104 class Thread: public ThreadShadow {
105 friend class Threads;
106 friend class VMStructs;
107 friend class JVMCIVMStructs;
108 private:
109
110 #ifndef USE_LIBRARY_BASED_TLS_ONLY
111 // Current thread is maintained as a thread-local variable
112 static THREAD_LOCAL_DECL Thread* _thr_current;
113 #endif
114
115 // Exception handling
116 // (Note: _pending_exception and friends are in ThreadShadow)
117 //oop _pending_exception; // pending exception for current thread
118 // const char* _exception_file; // file information for exception (debugging only)
119 // int _exception_line; // line information for exception (debugging only)
120 protected:
121 // Support for forcing alignment of thread objects for biased locking
122 void* _real_malloc_address;
123 // JavaThread lifecycle support:
124 friend class ScanHazardPtrGatherProtectedThreadsClosure;
125 friend class ScanHazardPtrGatherThreadsListClosure;
126 friend class ScanHazardPtrPrintMatchingThreadsClosure;
127 friend class ThreadsListHandle;
128 friend class ThreadsListSetter;
129 ThreadsList* volatile _threads_hazard_ptr;
130 ThreadsList* cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
131 ThreadsList* get_threads_hazard_ptr();
132 void set_threads_hazard_ptr(ThreadsList* new_list);
133 static bool is_hazard_ptr_tagged(ThreadsList* list) {
134 return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
135 }
136 static ThreadsList* tag_hazard_ptr(ThreadsList* list) {
137 return (ThreadsList*)(intptr_t(list) | intptr_t(1));
138 }
139 static ThreadsList* untag_hazard_ptr(ThreadsList* list) {
140 return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
141 }
142 NestedThreadsList* _nested_threads_hazard_ptr;
143 NestedThreadsList* get_nested_threads_hazard_ptr() {
144 return _nested_threads_hazard_ptr;
145 }
146 void set_nested_threads_hazard_ptr(NestedThreadsList* value) {
147 assert(Threads_lock->owned_by_self(),
148 "must own Threads_lock for _nested_threads_hazard_ptr to be valid.");
149 _nested_threads_hazard_ptr = value;
150 }
151 // This field is enabled via -XX:+EnableThreadSMRStatistics:
152 uint _nested_threads_hazard_ptr_cnt;
153 void dec_nested_threads_hazard_ptr_cnt() {
154 assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
155 _nested_threads_hazard_ptr_cnt--;
156 }
157 void inc_nested_threads_hazard_ptr_cnt() {
158 _nested_threads_hazard_ptr_cnt++;
159 }
160 uint nested_threads_hazard_ptr_cnt() {
161 return _nested_threads_hazard_ptr_cnt;
162 }
163
164 public:
165 void* operator new(size_t size) throw() { return allocate(size, true); }
166 void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
167 return allocate(size, false); }
168 void operator delete(void* p);
169
170 protected:
171 static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
172 private:
173
174 // ***************************************************************
175 // Suspend and resume support
176 // ***************************************************************
177 //
178 // VM suspend/resume no longer exists - it was once used for various
179 // things including safepoints but was deprecated and finally removed
180 // in Java 7. Because VM suspension was considered "internal" Java-level
181 // suspension was considered "external", and this legacy naming scheme
182 // remains.
183 //
184 // External suspend/resume requests come from JVM_SuspendThread,
185 // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
186 // ResumeThread. External
187 // suspend requests cause _external_suspend to be set and external
188 // resume requests cause _external_suspend to be cleared.
189 // External suspend requests do not nest on top of other external
190 // suspend requests. The higher level APIs reject suspend requests
191 // for already suspended threads.
192 //
193 // The external_suspend
194 // flag is checked by has_special_runtime_exit_condition() and java thread
195 // will self-suspend when handle_special_runtime_exit_condition() is
196 // called. Most uses of the _thread_blocked state in JavaThreads are
197 // considered the same as being externally suspended; if the blocking
198 // condition lifts, the JavaThread will self-suspend. Other places
199 // where VM checks for external_suspend include:
200 // + mutex granting (do not enter monitors when thread is suspended)
201 // + state transitions from _thread_in_native
202 //
203 // In general, java_suspend() does not wait for an external suspend
204 // request to complete. When it returns, the only guarantee is that
205 // the _external_suspend field is true.
206 //
207 // wait_for_ext_suspend_completion() is used to wait for an external
208 // suspend request to complete. External suspend requests are usually
209 // followed by some other interface call that requires the thread to
210 // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
211 // the interface that requires quiescence, we give the JavaThread a
212 // chance to self-suspend before we need it to be quiescent. This
213 // improves overall suspend/query performance.
214 //
215 // _suspend_flags controls the behavior of java_ suspend/resume.
216 // It must be set under the protection of SR_lock. Read from the flag is
217 // OK without SR_lock as long as the value is only used as a hint.
218 // (e.g., check _external_suspend first without lock and then recheck
219 // inside SR_lock and finish the suspension)
220 //
221 // _suspend_flags is also overloaded for other "special conditions" so
222 // that a single check indicates whether any special action is needed
223 // eg. for async exceptions.
224 // -------------------------------------------------------------------
225 // Notes:
226 // 1. The suspend/resume logic no longer uses ThreadState in OSThread
227 // but we still update its value to keep other part of the system (mainly
228 // JVMTI) happy. ThreadState is legacy code (see notes in
229 // osThread.hpp).
230 //
231 // 2. It would be more natural if set_external_suspend() is private and
232 // part of java_suspend(), but that probably would affect the suspend/query
233 // performance. Need more investigation on this.
234
235 // suspend/resume lock: used for self-suspend
236 Monitor* _SR_lock;
237
238 protected:
239 enum SuspendFlags {
240 // NOTE: avoid using the sign-bit as cc generates different test code
241 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
242
243 _external_suspend = 0x20000000U, // thread is asked to self suspend
244 _ext_suspended = 0x40000000U, // thread has self-suspended
245 _deopt_suspend = 0x10000000U, // thread needs to self suspend for deopt
246
247 _has_async_exception = 0x00000001U, // there is a pending async exception
248 _critical_native_unlock = 0x00000002U, // Must call back to unlock JNI critical lock
249
250 _trace_flag = 0x00000004U // call tracing backend
251 };
252
253 // various suspension related flags - atomically updated
254 // overloaded for async exception checking in check_special_condition_for_native_trans.
255 volatile uint32_t _suspend_flags;
256
257 private:
258 int _num_nested_signal;
259
260 DEBUG_ONLY(bool _suspendible_thread;)
261
262 public:
263 void enter_signal_handler() { _num_nested_signal++; }
264 void leave_signal_handler() { _num_nested_signal--; }
265 bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
266
267 #ifdef ASSERT
268 void set_suspendible_thread() {
269 _suspendible_thread = true;
270 }
271
272 void clear_suspendible_thread() {
273 _suspendible_thread = false;
274 }
275
276 bool is_suspendible_thread() { return _suspendible_thread; }
277 #endif
278
279 private:
280 // Active_handles points to a block of handles
281 JNIHandleBlock* _active_handles;
282
283 // One-element thread local free list
284 JNIHandleBlock* _free_handle_block;
285
286 // Point to the last handle mark
287 HandleMark* _last_handle_mark;
288
289 // The parity of the last strong_roots iteration in which this thread was
290 // claimed as a task.
291 int _oops_do_parity;
292
293 public:
294 void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; }
295 HandleMark* last_handle_mark() const { return _last_handle_mark; }
296 private:
297
298 // debug support for checking if code does allow safepoints or not
299 // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on
300 // mutex, or blocking on an object synchronizer (Java locking).
301 // If !allow_safepoint(), then an assertion failure will happen in any of the above cases
302 // If !allow_allocation(), then an assertion failure will happen during allocation
303 // (Hence, !allow_safepoint() => !allow_allocation()).
304 //
305 // The two classes NoSafepointVerifier and No_Allocation_Verifier are used to set these counters.
306 //
307 NOT_PRODUCT(int _allow_safepoint_count;) // If 0, thread allow a safepoint to happen
308 debug_only(int _allow_allocation_count;) // If 0, the thread is allowed to allocate oops.
309
310 // Used by SkipGCALot class.
311 NOT_PRODUCT(bool _skip_gcalot;) // Should we elide gc-a-lot?
312
313 friend class NoAllocVerifier;
314 friend class NoSafepointVerifier;
315 friend class PauseNoSafepointVerifier;
316 friend class GCLocker;
317
318 ThreadLocalAllocBuffer _tlab; // Thread-local eden
319 jlong _allocated_bytes; // Cumulative number of bytes allocated on
320 // the Java heap
321
322 mutable TRACE_DATA _trace_data; // Thread-local data for tracing
323
324 ThreadExt _ext;
325
326 int _vm_operation_started_count; // VM_Operation support
327 int _vm_operation_completed_count; // VM_Operation support
328
329 ObjectMonitor* _current_pending_monitor; // ObjectMonitor this thread
330 // is waiting to lock
331 bool _current_pending_monitor_is_from_java; // locking is from Java code
332
333 // ObjectMonitor on which this thread called Object.wait()
334 ObjectMonitor* _current_waiting_monitor;
335
336 // Private thread-local objectmonitor list - a simple cache organized as a SLL.
337 public:
338 ObjectMonitor* omFreeList;
339 int omFreeCount; // length of omFreeList
340 int omFreeProvision; // reload chunk size
341 ObjectMonitor* omInUseList; // SLL to track monitors in circulation
342 int omInUseCount; // length of omInUseList
343
344 #ifdef ASSERT
345 private:
346 bool _visited_for_critical_count;
347
348 public:
349 void set_visited_for_critical_count(bool z) { _visited_for_critical_count = z; }
350 bool was_visited_for_critical_count() const { return _visited_for_critical_count; }
351 #endif
352
353 public:
354 enum {
355 is_definitely_current_thread = true
356 };
357
358 // Constructor
359 Thread();
360 virtual ~Thread();
361
362 // Manage Thread::current()
363 void initialize_thread_current();
364 void clear_thread_current(); // TLS cleanup needed before threads terminate
365
366 public:
367 // thread entry point
368 virtual void run();
369
370 // Testers
371 virtual bool is_VM_thread() const { return false; }
372 virtual bool is_Java_thread() const { return false; }
373 virtual bool is_Compiler_thread() const { return false; }
374 virtual bool is_Code_cache_sweeper_thread() const { return false; }
375 virtual bool is_hidden_from_external_view() const { return false; }
376 virtual bool is_jvmti_agent_thread() const { return false; }
377 // True iff the thread can perform GC operations at a safepoint.
378 // Generally will be true only of VM thread and parallel GC WorkGang
379 // threads.
380 virtual bool is_GC_task_thread() const { return false; }
381 virtual bool is_Watcher_thread() const { return false; }
382 virtual bool is_ConcurrentGC_thread() const { return false; }
383 virtual bool is_Named_thread() const { return false; }
384 virtual bool is_Worker_thread() const { return false; }
385
386 // Can this thread make Java upcalls
387 virtual bool can_call_java() const { return false; }
388
389 // Casts
390 virtual WorkerThread* as_Worker_thread() const { return NULL; }
391
392 virtual char* name() const { return (char*)"Unknown thread"; }
393
394 // Returns the current thread (ASSERTS if NULL)
395 static inline Thread* current();
396 // Returns the current thread, or NULL if not attached
397 static inline Thread* current_or_null();
398 // Returns the current thread, or NULL if not attached, and is
399 // safe for use from signal-handlers
400 static inline Thread* current_or_null_safe();
401
402 // Common thread operations
403 #ifdef ASSERT
404 static void check_for_dangling_thread_pointer(Thread *thread);
405 #endif
406 static void set_priority(Thread* thread, ThreadPriority priority);
407 static ThreadPriority get_priority(const Thread* const thread);
408 static void start(Thread* thread);
409 static void interrupt(Thread* thr);
410 static bool is_interrupted(Thread* thr, bool clear_interrupted);
411
412 void set_native_thread_name(const char *name) {
413 assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
414 os::set_native_thread_name(name);
415 }
416
417 ObjectMonitor** omInUseList_addr() { return (ObjectMonitor **)&omInUseList; }
418 Monitor* SR_lock() const { return _SR_lock; }
419
420 bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
421
422 inline void set_suspend_flag(SuspendFlags f);
423 inline void clear_suspend_flag(SuspendFlags f);
424
425 inline void set_has_async_exception();
426 inline void clear_has_async_exception();
427
428 bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
429
430 inline void set_critical_native_unlock();
431 inline void clear_critical_native_unlock();
432
433 inline void set_trace_flag();
434 inline void clear_trace_flag();
435
436 // Support for Unhandled Oop detection
437 // Add the field for both, fastdebug and debug, builds to keep
438 // Thread's fields layout the same.
439 // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
440 #ifdef CHECK_UNHANDLED_OOPS
441 private:
442 UnhandledOops* _unhandled_oops;
443 #elif defined(ASSERT)
444 private:
445 void* _unhandled_oops;
446 #endif
447 #ifdef CHECK_UNHANDLED_OOPS
448 public:
449 UnhandledOops* unhandled_oops() { return _unhandled_oops; }
450 // Mark oop safe for gc. It may be stack allocated but won't move.
451 void allow_unhandled_oop(oop *op) {
452 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
453 }
454 // Clear oops at safepoint so crashes point to unhandled oop violator
455 void clear_unhandled_oops() {
456 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
457 }
458 #endif // CHECK_UNHANDLED_OOPS
459
460 public:
461 #ifndef PRODUCT
462 bool skip_gcalot() { return _skip_gcalot; }
463 void set_skip_gcalot(bool v) { _skip_gcalot = v; }
464 #endif
465
466 // Installs a pending exception to be inserted later
467 static void send_async_exception(oop thread_oop, oop java_throwable);
468
469 // Resource area
470 ResourceArea* resource_area() const { return _resource_area; }
471 void set_resource_area(ResourceArea* area) { _resource_area = area; }
472
473 OSThread* osthread() const { return _osthread; }
474 void set_osthread(OSThread* thread) { _osthread = thread; }
475
476 // JNI handle support
477 JNIHandleBlock* active_handles() const { return _active_handles; }
478 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
479 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
480 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
481
482 // Internal handle support
483 HandleArea* handle_area() const { return _handle_area; }
484 void set_handle_area(HandleArea* area) { _handle_area = area; }
485
486 GrowableArray<Metadata*>* metadata_handles() const { return _metadata_handles; }
487 void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
488
489 // Thread-Local Allocation Buffer (TLAB) support
490 ThreadLocalAllocBuffer& tlab() { return _tlab; }
491 void initialize_tlab() {
492 if (UseTLAB) {
493 tlab().initialize();
494 }
495 }
496
497 jlong allocated_bytes() { return _allocated_bytes; }
498 void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
499 void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
500 inline jlong cooked_allocated_bytes();
501
502 TRACE_DEFINE_THREAD_TRACE_DATA_OFFSET;
503 TRACE_DATA* trace_data() const { return &_trace_data; }
504 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; }
505
506 const ThreadExt& ext() const { return _ext; }
507 ThreadExt& ext() { return _ext; }
508
509 // VM operation support
510 int vm_operation_ticket() { return ++_vm_operation_started_count; }
511 int vm_operation_completed_count() { return _vm_operation_completed_count; }
512 void increment_vm_operation_completed_count() { _vm_operation_completed_count++; }
513
514 // For tracking the heavyweight monitor the thread is pending on.
515 ObjectMonitor* current_pending_monitor() {
516 return _current_pending_monitor;
517 }
518 void set_current_pending_monitor(ObjectMonitor* monitor) {
519 _current_pending_monitor = monitor;
520 }
521 void set_current_pending_monitor_is_from_java(bool from_java) {
522 _current_pending_monitor_is_from_java = from_java;
523 }
524 bool current_pending_monitor_is_from_java() {
525 return _current_pending_monitor_is_from_java;
526 }
527
528 // For tracking the ObjectMonitor on which this thread called Object.wait()
529 ObjectMonitor* current_waiting_monitor() {
530 return _current_waiting_monitor;
531 }
532 void set_current_waiting_monitor(ObjectMonitor* monitor) {
533 _current_waiting_monitor = monitor;
534 }
535
536 // GC support
537 // Apply "f->do_oop" to all root oops in "this".
538 // Used by JavaThread::oops_do.
539 // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
540 virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
541
542 // Handles the parallel case for the method below.
543 private:
544 bool claim_oops_do_par_case(int collection_parity);
545 public:
546 // Requires that "collection_parity" is that of the current roots
547 // iteration. If "is_par" is false, sets the parity of "this" to
548 // "collection_parity", and returns "true". If "is_par" is true,
549 // uses an atomic instruction to set the current threads parity to
550 // "collection_parity", if it is not already. Returns "true" iff the
551 // calling thread does the update, this indicates that the calling thread
552 // has claimed the thread's stack as a root groop in the current
553 // collection.
554 bool claim_oops_do(bool is_par, int collection_parity) {
555 if (!is_par) {
556 _oops_do_parity = collection_parity;
557 return true;
558 } else {
559 return claim_oops_do_par_case(collection_parity);
560 }
561 }
562
563 // jvmtiRedefineClasses support
564 void metadata_handles_do(void f(Metadata*));
565
566 // Used by fast lock support
567 virtual bool is_lock_owned(address adr) const;
568
569 // Check if address is in the stack of the thread (not just for locks).
570 // Warning: the method can only be used on the running thread
571 bool is_in_stack(address adr) const;
572 // Check if address is in the usable part of the stack (excludes protected
573 // guard pages)
574 bool is_in_usable_stack(address adr) const;
575
576 // Sets this thread as starting thread. Returns failure if thread
577 // creation fails due to lack of memory, too many threads etc.
578 bool set_as_starting_thread();
579
580 protected:
581 // OS data associated with the thread
582 OSThread* _osthread; // Platform-specific thread information
583
584 // Thread local resource area for temporary allocation within the VM
585 ResourceArea* _resource_area;
586
587 DEBUG_ONLY(ResourceMark* _current_resource_mark;)
588
589 // Thread local handle area for allocation of handles within the VM
590 HandleArea* _handle_area;
591 GrowableArray<Metadata*>* _metadata_handles;
592
593 // Support for stack overflow handling, get_thread, etc.
594 address _stack_base;
595 size_t _stack_size;
596 uintptr_t _self_raw_id; // used by get_thread (mutable)
597 int _lgrp_id;
598
599 public:
600 // Stack overflow support
601 address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
602 void set_stack_base(address base) { _stack_base = base; }
603 size_t stack_size() const { return _stack_size; }
604 void set_stack_size(size_t size) { _stack_size = size; }
605 address stack_end() const { return stack_base() - stack_size(); }
606 void record_stack_base_and_size();
607
608 bool on_local_stack(address adr) const {
609 // QQQ this has knowledge of direction, ought to be a stack method
610 return (_stack_base >= adr && adr >= stack_end());
611 }
612
613 uintptr_t self_raw_id() { return _self_raw_id; }
614 void set_self_raw_id(uintptr_t value) { _self_raw_id = value; }
615
616 int lgrp_id() const { return _lgrp_id; }
617 void set_lgrp_id(int value) { _lgrp_id = value; }
618
619 // Printing
620 virtual void print_on(outputStream* st) const;
621 virtual void print_nested_threads_hazard_ptrs_on(outputStream* st) const;
622 void print() const { print_on(tty); }
623 virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
624 void print_value_on(outputStream* st) const;
625
626 // Debug-only code
627 #ifdef ASSERT
628 private:
629 // Deadlock detection support for Mutex locks. List of locks own by thread.
630 Monitor* _owned_locks;
631 // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
632 // thus the friendship
633 friend class Mutex;
634 friend class Monitor;
635
636 public:
637 void print_owned_locks_on(outputStream* st) const;
638 void print_owned_locks() const { print_owned_locks_on(tty); }
639 Monitor* owned_locks() const { return _owned_locks; }
640 bool owns_locks() const { return owned_locks() != NULL; }
641 bool owns_locks_but_compiled_lock() const;
642 int oops_do_parity() const { return _oops_do_parity; }
643
644 // Deadlock detection
645 bool allow_allocation() { return _allow_allocation_count == 0; }
646 ResourceMark* current_resource_mark() { return _current_resource_mark; }
647 void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
648 #endif
649
650 void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN;
651
652 private:
653 volatile int _jvmti_env_iteration_count;
654
655 public:
656 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; }
657 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; }
658 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; }
659
660 // Code generation
661 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file); }
662 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line); }
663 static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles); }
664
665 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base); }
666 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size); }
667
668 #define TLAB_FIELD_OFFSET(name) \
669 static ByteSize tlab_##name##_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::name##_offset(); }
670
671 TLAB_FIELD_OFFSET(start)
672 TLAB_FIELD_OFFSET(end)
673 TLAB_FIELD_OFFSET(top)
674 TLAB_FIELD_OFFSET(pf_top)
675 TLAB_FIELD_OFFSET(size) // desired_size
676 TLAB_FIELD_OFFSET(refill_waste_limit)
677 TLAB_FIELD_OFFSET(number_of_refills)
678 TLAB_FIELD_OFFSET(fast_refill_waste)
679 TLAB_FIELD_OFFSET(slow_allocations)
680
681 #undef TLAB_FIELD_OFFSET
682
683 static ByteSize allocated_bytes_offset() { return byte_offset_of(Thread, _allocated_bytes); }
684
685 public:
686 volatile intptr_t _Stalled;
687 volatile int _TypeTag;
688 ParkEvent * _ParkEvent; // for synchronized()
689 ParkEvent * _SleepEvent; // for Thread.sleep
690 ParkEvent * _MutexEvent; // for native internal Mutex/Monitor
691 ParkEvent * _MuxEvent; // for low-level muxAcquire-muxRelease
692 int NativeSyncRecursion; // diagnostic
693
694 volatile int _OnTrap; // Resume-at IP delta
695 jint _hashStateW; // Marsaglia Shift-XOR thread-local RNG
696 jint _hashStateX; // thread-specific hashCode generator state
697 jint _hashStateY;
698 jint _hashStateZ;
699 void * _schedctl;
700
701
702 volatile jint rng[4]; // RNG for spin loop
703
704 // Low-level leaf-lock primitives used to implement synchronization
705 // and native monitor-mutex infrastructure.
706 // Not for general synchronization use.
707 static void SpinAcquire(volatile int * Lock, const char * Name);
708 static void SpinRelease(volatile int * Lock);
709 static void muxAcquire(volatile intptr_t * Lock, const char * Name);
710 static void muxAcquireW(volatile intptr_t * Lock, ParkEvent * ev);
711 static void muxRelease(volatile intptr_t * Lock);
712 };
713
714 // Inline implementation of Thread::current()
715 inline Thread* Thread::current() {
716 Thread* current = current_or_null();
717 assert(current != NULL, "Thread::current() called on detached thread");
718 return current;
719 }
720
721 inline Thread* Thread::current_or_null() {
722 #ifndef USE_LIBRARY_BASED_TLS_ONLY
723 return _thr_current;
724 #else
725 if (ThreadLocalStorage::is_initialized()) {
726 return ThreadLocalStorage::thread();
727 }
728 return NULL;
729 #endif
730 }
731
732 inline Thread* Thread::current_or_null_safe() {
733 if (ThreadLocalStorage::is_initialized()) {
734 return ThreadLocalStorage::thread();
735 }
736 return NULL;
737 }
738
739 // Name support for threads. non-JavaThread subclasses with multiple
740 // uniquely named instances should derive from this.
741 class NamedThread: public Thread {
742 friend class VMStructs;
743 enum {
744 max_name_len = 64
745 };
746 private:
747 char* _name;
748 // log JavaThread being processed by oops_do
749 JavaThread* _processed_thread;
750 uint _gc_id; // The current GC id when a thread takes part in GC
751
752 public:
753 NamedThread();
754 ~NamedThread();
755 // May only be called once per thread.
756 void set_name(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
757 void initialize_named_thread();
758 virtual bool is_Named_thread() const { return true; }
759 virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
760 JavaThread *processed_thread() { return _processed_thread; }
761 void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
762 virtual void print_on(outputStream* st) const;
763
764 void set_gc_id(uint gc_id) { _gc_id = gc_id; }
765 uint gc_id() { return _gc_id; }
766 };
767
768 // Worker threads are named and have an id of an assigned work.
769 class WorkerThread: public NamedThread {
770 private:
771 uint _id;
772 public:
773 WorkerThread() : _id(0) { }
774 virtual bool is_Worker_thread() const { return true; }
775
776 virtual WorkerThread* as_Worker_thread() const {
777 assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
778 return (WorkerThread*) this;
779 }
780
781 void set_id(uint work_id) { _id = work_id; }
782 uint id() const { return _id; }
783 };
784
785 // A single WatcherThread is used for simulating timer interrupts.
786 class WatcherThread: public Thread {
787 friend class VMStructs;
788 public:
789 virtual void run();
790
791 private:
792 static WatcherThread* _watcher_thread;
793
794 static bool _startable;
795 // volatile due to at least one lock-free read
796 volatile static bool _should_terminate;
797 public:
798 enum SomeConstants {
799 delay_interval = 10 // interrupt delay in milliseconds
800 };
801
802 // Constructor
803 WatcherThread();
804
805 // No destruction allowed
806 ~WatcherThread() {
807 guarantee(false, "WatcherThread deletion must fix the race with VM termination");
808 }
809
810 // Tester
811 bool is_Watcher_thread() const { return true; }
812
813 // Printing
814 char* name() const { return (char*)"VM Periodic Task Thread"; }
815 void print_on(outputStream* st) const;
816 void unpark();
817
818 // Returns the single instance of WatcherThread
819 static WatcherThread* watcher_thread() { return _watcher_thread; }
820
821 // Create and start the single instance of WatcherThread, or stop it on shutdown
822 static void start();
823 static void stop();
824 // Only allow start once the VM is sufficiently initialized
825 // Otherwise the first task to enroll will trigger the start
826 static void make_startable();
827 private:
828 int sleep() const;
829 };
830
831
832 class CompilerThread;
833
834 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
835
836 class JavaThread: public Thread {
837 friend class VMStructs;
838 friend class JVMCIVMStructs;
839 friend class WhiteBox;
840 private:
841 JavaThread* _next; // The next thread in the Threads list
842 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
843 oop _threadObj; // The Java level thread object
844
845 #ifdef ASSERT
846 private:
847 int _java_call_counter;
848
849 public:
850 int java_call_counter() { return _java_call_counter; }
851 void inc_java_call_counter() { _java_call_counter++; }
852 void dec_java_call_counter() {
853 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
854 _java_call_counter--;
855 }
856 private: // restore original namespace restriction
857 #endif // ifdef ASSERT
858
859 #ifndef PRODUCT
860 public:
861 enum {
862 jump_ring_buffer_size = 16
863 };
864 private: // restore original namespace restriction
865 #endif
866
867 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
868
869 ThreadFunction _entry_point;
870
871 JNIEnv _jni_environment;
872
873 // Deopt support
874 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
875
876 intptr_t* _must_deopt_id; // id of frame that needs to be deopted once we
877 // transition out of native
878 CompiledMethod* _deopt_nmethod; // CompiledMethod that is currently being deoptimized
879 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
880 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
881 // Because deoptimization is lazy we must save jvmti requests to set locals
882 // in compiled frames until we deoptimize and we have an interpreter frame.
883 // This holds the pointer to array (yeah like there might be more than one) of
884 // description of compiled vframes that have locals that need to be updated.
885 GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
886
887 // Handshake value for fixing 6243940. We need a place for the i2c
888 // adapter to store the callee Method*. This value is NEVER live
889 // across a gc point so it does NOT have to be gc'd
890 // The handshake is open ended since we can't be certain that it will
891 // be NULLed. This is because we rarely ever see the race and end up
892 // in handle_wrong_method which is the backend of the handshake. See
893 // code in i2c adapters and handle_wrong_method.
894
895 Method* _callee_target;
896
897 // Used to pass back results to the interpreter or generated code running Java code.
898 oop _vm_result; // oop result is GC-preserved
899 Metadata* _vm_result_2; // non-oop result
900
901 // See ReduceInitialCardMarks: this holds the precise space interval of
902 // the most recent slow path allocation for which compiled code has
903 // elided card-marks for performance along the fast-path.
904 MemRegion _deferred_card_mark;
905
906 MonitorChunk* _monitor_chunks; // Contains the off stack monitors
907 // allocated during deoptimization
908 // and by JNI_MonitorEnter/Exit
909
910 // Async. requests support
911 enum AsyncRequests {
912 _no_async_condition = 0,
913 _async_exception,
914 _async_unsafe_access_error
915 };
916 AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
917 oop _pending_async_exception;
918
919 // Safepoint support
920 public: // Expose _thread_state for SafeFetchInt()
921 volatile JavaThreadState _thread_state;
922 private:
923 ThreadSafepointState *_safepoint_state; // Holds information about a thread during a safepoint
924 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
925
926 // JavaThread termination support
927 enum TerminatedTypes {
928 _not_terminated = 0xDEAD - 2,
929 _thread_exiting, // JavaThread::exit() has been called for this thread
930 _thread_terminated, // JavaThread is removed from thread list
931 _vm_exited // JavaThread is still executing native code, but VM is terminated
932 // only VM_Exit can set _vm_exited
933 };
934
935 // In general a JavaThread's _terminated field transitions as follows:
936 //
937 // _not_terminated => _thread_exiting => _thread_terminated
938 //
939 // _vm_exited is a special value to cover the case of a JavaThread
940 // executing native code after the VM itself is terminated.
941 volatile TerminatedTypes _terminated;
942 // suspend/resume support
943 volatile bool _suspend_equivalent; // Suspend equivalent condition
944 jint _in_deopt_handler; // count of deoptimization
945 // handlers thread is in
946 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
947 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
948 // never locked) when throwing an exception. Used by interpreter only.
949
950 // JNI attach states:
951 enum JNIAttachStates {
952 _not_attaching_via_jni = 1, // thread is not attaching via JNI
953 _attaching_via_jni, // thread is attaching via JNI
954 _attached_via_jni // thread has attached via JNI
955 };
956
957 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
958 // A native thread that is attaching via JNI starts with a value
959 // of _attaching_via_jni and transitions to _attached_via_jni.
960 volatile JNIAttachStates _jni_attach_state;
961
962 public:
963 // State of the stack guard pages for this thread.
964 enum StackGuardState {
965 stack_guard_unused, // not needed
966 stack_guard_reserved_disabled,
967 stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
968 stack_guard_enabled // enabled
969 };
970
971 private:
972
973 #if INCLUDE_JVMCI
974 // The _pending_* fields below are used to communicate extra information
975 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
976
977 // Communicates the DeoptReason and DeoptAction of the uncommon trap
978 int _pending_deoptimization;
979
980 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
981 // before the monitor has been acquired.
982 bool _pending_monitorenter;
983
984 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
985 bool _pending_transfer_to_interpreter;
986
987 // Guard for re-entrant call to JVMCIRuntime::adjust_comp_level
988 bool _adjusting_comp_level;
989
990 // An object that JVMCI compiled code can use to further describe and
991 // uniquely identify the speculative optimization guarded by the uncommon trap
992 oop _pending_failed_speculation;
993
994 // These fields are mutually exclusive in terms of live ranges.
995 union {
996 // Communicates the pc at which the most recent implicit exception occurred
997 // from the signal handler to a deoptimization stub.
998 address _implicit_exception_pc;
999
1000 // Communicates an alternative call target to an i2c stub from a JavaCall .
1001 address _alternate_call_target;
1002 } _jvmci;
1003
1004 // Support for high precision, thread sensitive counters in JVMCI compiled code.
1005 jlong* _jvmci_counters;
1006
1007 public:
1008 static jlong* _jvmci_old_thread_counters;
1009 static void collect_counters(typeArrayOop array);
1010 private:
1011 #endif // INCLUDE_JVMCI
1012
1013 StackGuardState _stack_guard_state;
1014
1015 // Precompute the limit of the stack as used in stack overflow checks.
1016 // We load it from here to simplify the stack overflow check in assembly.
1017 address _stack_overflow_limit;
1018 address _reserved_stack_activation;
1019
1020 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1021 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1022 // code)
1023 volatile oop _exception_oop; // Exception thrown in compiled code
1024 volatile address _exception_pc; // PC where exception happened
1025 volatile address _exception_handler_pc; // PC for handler of exception
1026 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
1027
1028 private:
1029 // support for JNI critical regions
1030 jint _jni_active_critical; // count of entries into JNI critical region
1031
1032 // Checked JNI: function name requires exception check
1033 char* _pending_jni_exception_check_fn;
1034
1035 // For deadlock detection.
1036 int _depth_first_number;
1037
1038 // JVMTI PopFrame support
1039 // This is set to popframe_pending to signal that top Java frame should be popped immediately
1040 int _popframe_condition;
1041
1042 // If reallocation of scalar replaced objects fails, we throw OOM
1043 // and during exception propagation, pop the top
1044 // _frames_to_pop_failed_realloc frames, the ones that reference
1045 // failed reallocations.
1046 int _frames_to_pop_failed_realloc;
1047
1048 #ifndef PRODUCT
1049 int _jmp_ring_index;
1050 struct {
1051 // We use intptr_t instead of address so debugger doesn't try and display strings
1052 intptr_t _target;
1053 intptr_t _instruction;
1054 const char* _file;
1055 int _line;
1056 } _jmp_ring[jump_ring_buffer_size];
1057 #endif // PRODUCT
1058
1059 #if INCLUDE_ALL_GCS
1060 // Support for G1 barriers
1061
1062 SATBMarkQueue _satb_mark_queue; // Thread-local log for SATB barrier.
1063 // Set of all such queues.
1064 static SATBMarkQueueSet _satb_mark_queue_set;
1065
1066 DirtyCardQueue _dirty_card_queue; // Thread-local log for dirty cards.
1067 // Set of all such queues.
1068 static DirtyCardQueueSet _dirty_card_queue_set;
1069
1070 void flush_barrier_queues();
1071 #endif // INCLUDE_ALL_GCS
1072
1073 friend class VMThread;
1074 friend class ThreadWaitTransition;
1075 friend class VM_Exit;
1076
1077 void initialize(); // Initialized the instance variables
1078
1079 public:
1080 // Constructor
1081 JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1082 JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1083 ~JavaThread();
1084
1085 #ifdef ASSERT
1086 // verify this JavaThread hasn't be published in the Threads::list yet
1087 void verify_not_published();
1088 #endif
1089
1090 //JNI functiontable getter/setter for JVMTI jni function table interception API.
1091 void set_jni_functions(struct JNINativeInterface_* functionTable) {
1092 _jni_environment.functions = functionTable;
1093 }
1094 struct JNINativeInterface_* get_jni_functions() {
1095 return (struct JNINativeInterface_ *)_jni_environment.functions;
1096 }
1097
1098 // This function is called at thread creation to allow
1099 // platform specific thread variables to be initialized.
1100 void cache_global_variables();
1101
1102 // Executes Shutdown.shutdown()
1103 void invoke_shutdown_hooks();
1104
1105 // Cleanup on thread exit
1106 enum ExitType {
1107 normal_exit,
1108 jni_detach
1109 };
1110 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1111
1112 void cleanup_failed_attach_current_thread();
1113
1114 // Testers
1115 virtual bool is_Java_thread() const { return true; }
1116 virtual bool can_call_java() const { return true; }
1117
1118 // Thread chain operations
1119 JavaThread* next() const { return _next; }
1120 void set_next(JavaThread* p) { _next = p; }
1121
1122 // Thread oop. threadObj() can be NULL for initial JavaThread
1123 // (or for threads attached via JNI)
1124 oop threadObj() const { return _threadObj; }
1125 void set_threadObj(oop p) { _threadObj = p; }
1126
1127 ThreadPriority java_priority() const; // Read from threadObj()
1128
1129 // Prepare thread and add to priority queue. If a priority is
1130 // not specified, use the priority of the thread object. Threads_lock
1131 // must be held while this function is called.
1132 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1133 void prepare_ext();
1134
1135 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
1136 address saved_exception_pc() { return _saved_exception_pc; }
1137
1138
1139 ThreadFunction entry_point() const { return _entry_point; }
1140
1141 // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1142 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1143
1144 // Last frame anchor routines
1145
1146 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
1147
1148 // last_Java_sp
1149 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
1150 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
1151
1152 // last_Java_pc
1153
1154 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
1155
1156 // Safepoint support
1157 #if !(defined(PPC64) || defined(AARCH64))
1158 JavaThreadState thread_state() const { return _thread_state; }
1159 void set_thread_state(JavaThreadState s) { _thread_state = s; }
1160 #else
1161 // Use membars when accessing volatile _thread_state. See
1162 // Threads::create_vm() for size checks.
1163 inline JavaThreadState thread_state() const;
1164 inline void set_thread_state(JavaThreadState s);
1165 #endif
1166 ThreadSafepointState *safepoint_state() const { return _safepoint_state; }
1167 void set_safepoint_state(ThreadSafepointState *state) { _safepoint_state = state; }
1168 bool is_at_poll_safepoint() { return _safepoint_state->is_at_poll_safepoint(); }
1169
1170 // JavaThread termination and lifecycle support:
1171 void smr_delete();
1172 bool on_thread_list() { return _on_thread_list; }
1173 void set_on_thread_list() { _on_thread_list = true; }
1174
1175 // thread has called JavaThread::exit() or is terminated
1176 bool is_exiting() const;
1177 // thread is terminated (no longer on the threads list); we compare
1178 // against the two non-terminated values so that a freed JavaThread
1179 // will also be considered terminated.
1180 bool check_is_terminated(TerminatedTypes l_terminated) const {
1181 return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1182 }
1183 bool is_terminated();
1184 void set_terminated(TerminatedTypes t);
1185 // special for Threads::remove() which is static:
1186 void set_terminated_value();
1187 void block_if_vm_exited();
1188
1189 bool doing_unsafe_access() { return _doing_unsafe_access; }
1190 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
1191
1192 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
1193 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1194
1195 // Suspend/resume support for JavaThread
1196 private:
1197 inline void set_ext_suspended();
1198 inline void clear_ext_suspended();
1199
1200 public:
1201 void java_suspend();
1202 void java_resume();
1203 int java_suspend_self();
1204
1205 void check_and_wait_while_suspended() {
1206 assert(JavaThread::current() == this, "sanity check");
1207
1208 bool do_self_suspend;
1209 do {
1210 // were we externally suspended while we were waiting?
1211 do_self_suspend = handle_special_suspend_equivalent_condition();
1212 if (do_self_suspend) {
1213 // don't surprise the thread that suspended us by returning
1214 java_suspend_self();
1215 set_suspend_equivalent();
1216 }
1217 } while (do_self_suspend);
1218 }
1219 static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1220 // Check for async exception in addition to safepoint and suspend request.
1221 static void check_special_condition_for_native_trans(JavaThread *thread);
1222
1223 // Same as check_special_condition_for_native_trans but finishes the
1224 // transition into thread_in_Java mode so that it can potentially
1225 // block.
1226 static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1227
1228 bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1229 bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1230 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1231 // Warning: is_ext_suspend_completed() may temporarily drop the
1232 // SR_lock to allow the thread to reach a stable thread state if
1233 // it is currently in a transient thread state.
1234 return is_ext_suspend_completed(false /* !called_by_wait */,
1235 SuspendRetryDelay, bits);
1236 }
1237
1238 // We cannot allow wait_for_ext_suspend_completion() to run forever or
1239 // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1240 // passed as the count and delay parameters. Experiments with specific
1241 // calls to wait_for_ext_suspend_completion() can be done by passing
1242 // other values in the code. Experiments with all calls can be done
1243 // via the appropriate -XX options.
1244 bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1245
1246 // test for suspend - most (all?) of these should go away
1247 bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits);
1248
1249 inline void set_external_suspend();
1250 inline void clear_external_suspend();
1251
1252 inline void set_deopt_suspend();
1253 inline void clear_deopt_suspend();
1254 bool is_deopt_suspend() { return (_suspend_flags & _deopt_suspend) != 0; }
1255
1256 bool is_external_suspend() const {
1257 return (_suspend_flags & _external_suspend) != 0;
1258 }
1259 // Whenever a thread transitions from native to vm/java it must suspend
1260 // if external|deopt suspend is present.
1261 bool is_suspend_after_native() const {
1262 return (_suspend_flags & (_external_suspend | _deopt_suspend)) != 0;
1263 }
1264
1265 // external suspend request is completed
1266 bool is_ext_suspended() const {
1267 return (_suspend_flags & _ext_suspended) != 0;
1268 }
1269
1270 bool is_external_suspend_with_lock() const {
1271 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1272 return is_external_suspend();
1273 }
1274
1275 // Special method to handle a pending external suspend request
1276 // when a suspend equivalent condition lifts.
1277 bool handle_special_suspend_equivalent_condition() {
1278 assert(is_suspend_equivalent(),
1279 "should only be called in a suspend equivalence condition");
1280 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1281 bool ret = is_external_suspend();
1282 if (!ret) {
1283 // not about to self-suspend so clear suspend equivalence
1284 clear_suspend_equivalent();
1285 }
1286 // implied else:
1287 // We have a pending external suspend request so we leave the
1288 // suspend_equivalent flag set until java_suspend_self() sets
1289 // the ext_suspended flag and clears the suspend_equivalent
1290 // flag. This insures that wait_for_ext_suspend_completion()
1291 // will return consistent values.
1292 return ret;
1293 }
1294
1295 // utility methods to see if we are doing some kind of suspension
1296 bool is_being_ext_suspended() const {
1297 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1298 return is_ext_suspended() || is_external_suspend();
1299 }
1300
1301 bool is_suspend_equivalent() const { return _suspend_equivalent; }
1302
1303 void set_suspend_equivalent() { _suspend_equivalent = true; }
1304 void clear_suspend_equivalent() { _suspend_equivalent = false; }
1305
1306 // Thread.stop support
1307 void send_thread_stop(oop throwable);
1308 AsyncRequests clear_special_runtime_exit_condition() {
1309 AsyncRequests x = _special_runtime_exit_condition;
1310 _special_runtime_exit_condition = _no_async_condition;
1311 return x;
1312 }
1313
1314 // Are any async conditions present?
1315 bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1316
1317 void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1318
1319 // these next two are also used for self-suspension and async exception support
1320 void handle_special_runtime_exit_condition(bool check_asyncs = true);
1321
1322 // Return true if JavaThread has an asynchronous condition or
1323 // if external suspension is requested.
1324 bool has_special_runtime_exit_condition() {
1325 // Because we don't use is_external_suspend_with_lock
1326 // it is possible that we won't see an asynchronous external suspend
1327 // request that has just gotten started, i.e., SR_lock grabbed but
1328 // _external_suspend field change either not made yet or not visible
1329 // yet. However, this is okay because the request is asynchronous and
1330 // we will see the new flag value the next time through. It's also
1331 // possible that the external suspend request is dropped after
1332 // we have checked is_external_suspend(), we will recheck its value
1333 // under SR_lock in java_suspend_self().
1334 return (_special_runtime_exit_condition != _no_async_condition) ||
1335 is_external_suspend() || is_trace_suspend();
1336 }
1337
1338 void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; }
1339
1340 inline void set_pending_async_exception(oop e);
1341
1342 // Fast-locking support
1343 bool is_lock_owned(address adr) const;
1344
1345 // Accessors for vframe array top
1346 // The linked list of vframe arrays are sorted on sp. This means when we
1347 // unpack the head must contain the vframe array to unpack.
1348 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1349 vframeArray* vframe_array_head() const { return _vframe_array_head; }
1350
1351 // Side structure for deferring update of java frame locals until deopt occurs
1352 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1353 void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1354
1355 // These only really exist to make debugging deopt problems simpler
1356
1357 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1358 vframeArray* vframe_array_last() const { return _vframe_array_last; }
1359
1360 // The special resourceMark used during deoptimization
1361
1362 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
1363 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
1364
1365 intptr_t* must_deopt_id() { return _must_deopt_id; }
1366 void set_must_deopt_id(intptr_t* id) { _must_deopt_id = id; }
1367 void clear_must_deopt_id() { _must_deopt_id = NULL; }
1368
1369 void set_deopt_compiled_method(CompiledMethod* nm) { _deopt_nmethod = nm; }
1370 CompiledMethod* deopt_compiled_method() { return _deopt_nmethod; }
1371
1372 Method* callee_target() const { return _callee_target; }
1373 void set_callee_target (Method* x) { _callee_target = x; }
1374
1375 // Oop results of vm runtime calls
1376 oop vm_result() const { return _vm_result; }
1377 void set_vm_result (oop x) { _vm_result = x; }
1378
1379 Metadata* vm_result_2() const { return _vm_result_2; }
1380 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
1381
1382 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
1383 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
1384
1385 #if INCLUDE_JVMCI
1386 int pending_deoptimization() const { return _pending_deoptimization; }
1387 oop pending_failed_speculation() const { return _pending_failed_speculation; }
1388 bool adjusting_comp_level() const { return _adjusting_comp_level; }
1389 void set_adjusting_comp_level(bool b) { _adjusting_comp_level = b; }
1390 bool has_pending_monitorenter() const { return _pending_monitorenter; }
1391 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
1392 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
1393 void set_pending_failed_speculation(oop failed_speculation) { _pending_failed_speculation = failed_speculation; }
1394 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1395 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1396 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1397 #endif // INCLUDE_JVMCI
1398
1399 // Exception handling for compiled methods
1400 oop exception_oop() const { return _exception_oop; }
1401 address exception_pc() const { return _exception_pc; }
1402 address exception_handler_pc() const { return _exception_handler_pc; }
1403 bool is_method_handle_return() const { return _is_method_handle_return == 1; }
1404
1405 void set_exception_oop(oop o) { (void)const_cast<oop&>(_exception_oop = o); }
1406 void set_exception_pc(address a) { _exception_pc = a; }
1407 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
1408 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
1409
1410 void clear_exception_oop_and_pc() {
1411 set_exception_oop(NULL);
1412 set_exception_pc(NULL);
1413 }
1414
1415 // Stack overflow support
1416 //
1417 // (small addresses)
1418 //
1419 // -- <-- stack_end() ---
1420 // | |
1421 // | red pages |
1422 // | |
1423 // -- <-- stack_red_zone_base() |
1424 // | |
1425 // | guard
1426 // | yellow pages zone
1427 // | |
1428 // | |
1429 // -- <-- stack_yellow_zone_base() |
1430 // | |
1431 // | |
1432 // | reserved pages |
1433 // | |
1434 // -- <-- stack_reserved_zone_base() --- ---
1435 // /|\ shadow <-- stack_overflow_limit() (somewhere in here)
1436 // | zone
1437 // \|/ size
1438 // some untouched memory ---
1439 //
1440 //
1441 // --
1442 // |
1443 // | shadow zone
1444 // |
1445 // --
1446 // x frame n
1447 // --
1448 // x frame n-1
1449 // x
1450 // --
1451 // ...
1452 //
1453 // --
1454 // x frame 0
1455 // -- <-- stack_base()
1456 //
1457 // (large addresses)
1458 //
1459
1460 private:
1461 // These values are derived from flags StackRedPages, StackYellowPages,
1462 // StackReservedPages and StackShadowPages. The zone size is determined
1463 // ergonomically if page_size > 4K.
1464 static size_t _stack_red_zone_size;
1465 static size_t _stack_yellow_zone_size;
1466 static size_t _stack_reserved_zone_size;
1467 static size_t _stack_shadow_zone_size;
1468 public:
1469 inline size_t stack_available(address cur_sp);
1470
1471 static size_t stack_red_zone_size() {
1472 assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1473 return _stack_red_zone_size;
1474 }
1475 static void set_stack_red_zone_size(size_t s) {
1476 assert(is_aligned(s, os::vm_page_size()),
1477 "We can not protect if the red zone size is not page aligned.");
1478 assert(_stack_red_zone_size == 0, "This should be called only once.");
1479 _stack_red_zone_size = s;
1480 }
1481 address stack_red_zone_base() {
1482 return (address)(stack_end() + stack_red_zone_size());
1483 }
1484 bool in_stack_red_zone(address a) {
1485 return a <= stack_red_zone_base() && a >= stack_end();
1486 }
1487
1488 static size_t stack_yellow_zone_size() {
1489 assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1490 return _stack_yellow_zone_size;
1491 }
1492 static void set_stack_yellow_zone_size(size_t s) {
1493 assert(is_aligned(s, os::vm_page_size()),
1494 "We can not protect if the yellow zone size is not page aligned.");
1495 assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1496 _stack_yellow_zone_size = s;
1497 }
1498
1499 static size_t stack_reserved_zone_size() {
1500 // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1501 return _stack_reserved_zone_size;
1502 }
1503 static void set_stack_reserved_zone_size(size_t s) {
1504 assert(is_aligned(s, os::vm_page_size()),
1505 "We can not protect if the reserved zone size is not page aligned.");
1506 assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1507 _stack_reserved_zone_size = s;
1508 }
1509 address stack_reserved_zone_base() {
1510 return (address)(stack_end() +
1511 (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1512 }
1513 bool in_stack_reserved_zone(address a) {
1514 return (a <= stack_reserved_zone_base()) &&
1515 (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1516 }
1517
1518 static size_t stack_yellow_reserved_zone_size() {
1519 return _stack_yellow_zone_size + _stack_reserved_zone_size;
1520 }
1521 bool in_stack_yellow_reserved_zone(address a) {
1522 return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1523 }
1524
1525 // Size of red + yellow + reserved zones.
1526 static size_t stack_guard_zone_size() {
1527 return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1528 }
1529
1530 static size_t stack_shadow_zone_size() {
1531 assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1532 return _stack_shadow_zone_size;
1533 }
1534 static void set_stack_shadow_zone_size(size_t s) {
1535 // The shadow area is not allocated or protected, so
1536 // it needs not be page aligned.
1537 // But the stack bang currently assumes that it is a
1538 // multiple of page size. This guarantees that the bang
1539 // loop touches all pages in the shadow zone.
1540 // This can be guaranteed differently, as well. E.g., if
1541 // the page size is a multiple of 4K, banging in 4K steps
1542 // suffices to touch all pages. (Some pages are banged
1543 // several times, though.)
1544 assert(is_aligned(s, os::vm_page_size()),
1545 "Stack bang assumes multiple of page size.");
1546 assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1547 _stack_shadow_zone_size = s;
1548 }
1549
1550 void create_stack_guard_pages();
1551 void remove_stack_guard_pages();
1552
1553 void enable_stack_reserved_zone();
1554 void disable_stack_reserved_zone();
1555 void enable_stack_yellow_reserved_zone();
1556 void disable_stack_yellow_reserved_zone();
1557 void enable_stack_red_zone();
1558 void disable_stack_red_zone();
1559
1560 inline bool stack_guard_zone_unused();
1561 inline bool stack_yellow_reserved_zone_disabled();
1562 inline bool stack_reserved_zone_disabled();
1563 inline bool stack_guards_enabled();
1564
1565 address reserved_stack_activation() const { return _reserved_stack_activation; }
1566 void set_reserved_stack_activation(address addr) {
1567 assert(_reserved_stack_activation == stack_base()
1568 || _reserved_stack_activation == NULL
1569 || addr == stack_base(), "Must not be set twice");
1570 _reserved_stack_activation = addr;
1571 }
1572
1573 // Attempt to reguard the stack after a stack overflow may have occurred.
1574 // Returns true if (a) guard pages are not needed on this thread, (b) the
1575 // pages are already guarded, or (c) the pages were successfully reguarded.
1576 // Returns false if there is not enough stack space to reguard the pages, in
1577 // which case the caller should unwind a frame and try again. The argument
1578 // should be the caller's (approximate) sp.
1579 bool reguard_stack(address cur_sp);
1580 // Similar to above but see if current stackpoint is out of the guard area
1581 // and reguard if possible.
1582 bool reguard_stack(void);
1583
1584 address stack_overflow_limit() { return _stack_overflow_limit; }
1585 void set_stack_overflow_limit() {
1586 _stack_overflow_limit =
1587 stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1588 }
1589
1590 // Misc. accessors/mutators
1591 void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; }
1592 void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; }
1593 bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; }
1594
1595 #ifndef PRODUCT
1596 void record_jump(address target, address instr, const char* file, int line);
1597 #endif // PRODUCT
1598
1599 // For assembly stub generation
1600 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
1601 #ifndef PRODUCT
1602 static ByteSize jmp_ring_index_offset() { return byte_offset_of(JavaThread, _jmp_ring_index); }
1603 static ByteSize jmp_ring_offset() { return byte_offset_of(JavaThread, _jmp_ring); }
1604 #endif // PRODUCT
1605 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
1606 static ByteSize pending_jni_exception_check_fn_offset() {
1607 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1608 }
1609 static ByteSize last_Java_sp_offset() {
1610 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1611 }
1612 static ByteSize last_Java_pc_offset() {
1613 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1614 }
1615 static ByteSize frame_anchor_offset() {
1616 return byte_offset_of(JavaThread, _anchor);
1617 }
1618 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
1619 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); }
1620 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); }
1621 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
1622 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
1623 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
1624 #if INCLUDE_JVMCI
1625 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1626 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
1627 static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1628 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1629 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1630 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
1631 #endif // INCLUDE_JVMCI
1632 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
1633 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
1634 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
1635 static ByteSize stack_overflow_limit_offset() { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1636 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1637 static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state); }
1638 static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1639 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
1640
1641 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1642 static ByteSize should_post_on_exceptions_flag_offset() {
1643 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1644 }
1645
1646 #if INCLUDE_ALL_GCS
1647 static ByteSize satb_mark_queue_offset() { return byte_offset_of(JavaThread, _satb_mark_queue); }
1648 static ByteSize dirty_card_queue_offset() { return byte_offset_of(JavaThread, _dirty_card_queue); }
1649 #endif // INCLUDE_ALL_GCS
1650
1651 // Returns the jni environment for this thread
1652 JNIEnv* jni_environment() { return &_jni_environment; }
1653
1654 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1655 JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1656 // Only return NULL if thread is off the thread list; starting to
1657 // exit should not return NULL.
1658 if (thread_from_jni_env->is_terminated()) {
1659 thread_from_jni_env->block_if_vm_exited();
1660 return NULL;
1661 } else {
1662 return thread_from_jni_env;
1663 }
1664 }
1665
1666 // JNI critical regions. These can nest.
1667 bool in_critical() { return _jni_active_critical > 0; }
1668 bool in_last_critical() { return _jni_active_critical == 1; }
1669 void enter_critical() {
1670 assert(Thread::current() == this ||
1671 (Thread::current()->is_VM_thread() &&
1672 SafepointSynchronize::is_synchronizing()),
1673 "this must be current thread or synchronizing");
1674 _jni_active_critical++;
1675 }
1676 void exit_critical() {
1677 assert(Thread::current() == this, "this must be current thread");
1678 _jni_active_critical--;
1679 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1680 }
1681
1682 // Checked JNI: is the programmer required to check for exceptions, if so specify
1683 // which function name. Returning to a Java frame should implicitly clear the
1684 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1685 // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1686 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1687 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1688 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1689 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1690 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1691
1692 // For deadlock detection
1693 int depth_first_number() { return _depth_first_number; }
1694 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1695
1696 private:
1697 void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1698
1699 public:
1700 MonitorChunk* monitor_chunks() const { return _monitor_chunks; }
1701 void add_monitor_chunk(MonitorChunk* chunk);
1702 void remove_monitor_chunk(MonitorChunk* chunk);
1703 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
1704 void inc_in_deopt_handler() { _in_deopt_handler++; }
1705 void dec_in_deopt_handler() {
1706 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1707 if (_in_deopt_handler > 0) { // robustness
1708 _in_deopt_handler--;
1709 }
1710 }
1711
1712 private:
1713 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1714
1715 public:
1716
1717 // Frame iteration; calls the function f for all frames on the stack
1718 void frames_do(void f(frame*, const RegisterMap*));
1719
1720 // Memory operations
1721 void oops_do(OopClosure* f, CodeBlobClosure* cf);
1722
1723 // Sweeper operations
1724 virtual void nmethods_do(CodeBlobClosure* cf);
1725
1726 // RedefineClasses Support
1727 void metadata_do(void f(Metadata*));
1728
1729 // Misc. operations
1730 char* name() const { return (char*)get_thread_name(); }
1731 void print_on(outputStream* st) const;
1732 void print_value();
1733 void print_thread_state_on(outputStream*) const PRODUCT_RETURN;
1734 void print_thread_state() const PRODUCT_RETURN;
1735 void print_on_error(outputStream* st, char* buf, int buflen) const;
1736 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1737 void verify();
1738 const char* get_thread_name() const;
1739 private:
1740 // factor out low-level mechanics for use in both normal and error cases
1741 const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1742 public:
1743 const char* get_threadgroup_name() const;
1744 const char* get_parent_name() const;
1745
1746 // Accessing frames
1747 frame last_frame() {
1748 _anchor.make_walkable(this);
1749 return pd_last_frame();
1750 }
1751 javaVFrame* last_java_vframe(RegisterMap* reg_map);
1752
1753 // Returns method at 'depth' java or native frames down the stack
1754 // Used for security checks
1755 Klass* security_get_caller_class(int depth);
1756
1757 // Print stack trace in external format
1758 void print_stack_on(outputStream* st);
1759 void print_stack() { print_stack_on(tty); }
1760
1761 // Print stack traces in various internal formats
1762 void trace_stack() PRODUCT_RETURN;
1763 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1764 void trace_frames() PRODUCT_RETURN;
1765 void trace_oops() PRODUCT_RETURN;
1766
1767 // Print an annotated view of the stack frames
1768 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1769 void validate_frame_layout() {
1770 print_frame_layout(0, true);
1771 }
1772
1773 // Returns the number of stack frames on the stack
1774 int depth() const;
1775
1776 // Function for testing deoptimization
1777 void deoptimize();
1778 void make_zombies();
1779
1780 void deoptimized_wrt_marked_nmethods();
1781
1782 public:
1783 // Returns the running thread as a JavaThread
1784 static inline JavaThread* current();
1785
1786 // Returns the active Java thread. Do not use this if you know you are calling
1787 // from a JavaThread, as it's slower than JavaThread::current. If called from
1788 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1789 // operation. You may not want that either.
1790 static JavaThread* active();
1791
1792 inline CompilerThread* as_CompilerThread();
1793
1794 public:
1795 virtual void run();
1796 void thread_main_inner();
1797
1798 private:
1799 // PRIVILEGED STACK
1800 PrivilegedElement* _privileged_stack_top;
1801 GrowableArray<oop>* _array_for_gc;
1802 public:
1803
1804 // Returns the privileged_stack information.
1805 PrivilegedElement* privileged_stack_top() const { return _privileged_stack_top; }
1806 void set_privileged_stack_top(PrivilegedElement *e) { _privileged_stack_top = e; }
1807 void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1808
1809 public:
1810 // Thread local information maintained by JVMTI.
1811 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1812 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1813 // getter is used to get this JavaThread's JvmtiThreadState if it has
1814 // one which means NULL can be returned. JvmtiThreadState::state_for()
1815 // is used to get the specified JavaThread's JvmtiThreadState if it has
1816 // one or it allocates a new JvmtiThreadState for the JavaThread and
1817 // returns it. JvmtiThreadState::state_for() will return NULL only if
1818 // the specified JavaThread is exiting.
1819 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1820 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1821 void set_jvmti_get_loaded_classes_closure(JvmtiGetLoadedClassesClosure* value) { _jvmti_get_loaded_classes_closure = value; }
1822 JvmtiGetLoadedClassesClosure* get_jvmti_get_loaded_classes_closure() const { return _jvmti_get_loaded_classes_closure; }
1823
1824 // JVMTI PopFrame support
1825 // Setting and clearing popframe_condition
1826 // All of these enumerated values are bits. popframe_pending
1827 // indicates that a PopFrame() has been requested and not yet been
1828 // completed. popframe_processing indicates that that PopFrame() is in
1829 // the process of being completed. popframe_force_deopt_reexecution_bit
1830 // indicates that special handling is required when returning to a
1831 // deoptimized caller.
1832 enum PopCondition {
1833 popframe_inactive = 0x00,
1834 popframe_pending_bit = 0x01,
1835 popframe_processing_bit = 0x02,
1836 popframe_force_deopt_reexecution_bit = 0x04
1837 };
1838 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1839 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1840 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1841 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1842 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1843 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1844 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1845 void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1846 #ifdef CC_INTERP
1847 bool pop_frame_pending(void) { return ((_popframe_condition & popframe_pending_bit) != 0); }
1848 void clr_pop_frame_pending(void) { _popframe_condition = popframe_inactive; }
1849 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1850 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
1851 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
1852 #endif
1853
1854 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
1855 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
1856 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
1857
1858 private:
1859 // Saved incoming arguments to popped frame.
1860 // Used only when popped interpreted frame returns to deoptimized frame.
1861 void* _popframe_preserved_args;
1862 int _popframe_preserved_args_size;
1863
1864 public:
1865 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
1866 void* popframe_preserved_args();
1867 ByteSize popframe_preserved_args_size();
1868 WordSize popframe_preserved_args_size_in_words();
1869 void popframe_free_preserved_args();
1870
1871
1872 private:
1873 JvmtiThreadState *_jvmti_thread_state;
1874 JvmtiGetLoadedClassesClosure* _jvmti_get_loaded_classes_closure;
1875
1876 // Used by the interpreter in fullspeed mode for frame pop, method
1877 // entry, method exit and single stepping support. This field is
1878 // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
1879 // It can be set to zero asynchronously (i.e., without a VM operation
1880 // or a lock) so we have to be very careful.
1881 int _interp_only_mode;
1882
1883 public:
1884 // used by the interpreter for fullspeed debugging support (see above)
1885 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1886 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
1887 int get_interp_only_mode() { return _interp_only_mode; }
1888 void increment_interp_only_mode() { ++_interp_only_mode; }
1889 void decrement_interp_only_mode() { --_interp_only_mode; }
1890
1891 // support for cached flag that indicates whether exceptions need to be posted for this thread
1892 // if this is false, we can avoid deoptimizing when events are thrown
1893 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1894 private:
1895 int _should_post_on_exceptions_flag;
1896
1897 public:
1898 int should_post_on_exceptions_flag() { return _should_post_on_exceptions_flag; }
1899 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
1900
1901 private:
1902 ThreadStatistics *_thread_stat;
1903
1904 public:
1905 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
1906
1907 // Return a blocker object for which this thread is blocked parking.
1908 oop current_park_blocker();
1909
1910 private:
1911 static size_t _stack_size_at_create;
1912
1913 public:
1914 static inline size_t stack_size_at_create(void) {
1915 return _stack_size_at_create;
1916 }
1917 static inline void set_stack_size_at_create(size_t value) {
1918 _stack_size_at_create = value;
1919 }
1920
1921 #if INCLUDE_ALL_GCS
1922 // SATB marking queue support
1923 SATBMarkQueue& satb_mark_queue() { return _satb_mark_queue; }
1924 static SATBMarkQueueSet& satb_mark_queue_set() {
1925 return _satb_mark_queue_set;
1926 }
1927
1928 // Dirty card queue support
1929 DirtyCardQueue& dirty_card_queue() { return _dirty_card_queue; }
1930 static DirtyCardQueueSet& dirty_card_queue_set() {
1931 return _dirty_card_queue_set;
1932 }
1933 #endif // INCLUDE_ALL_GCS
1934
1935 // This method initializes the SATB and dirty card queues before a
1936 // JavaThread is added to the Java thread list. Right now, we don't
1937 // have to do anything to the dirty card queue (it should have been
1938 // activated when the thread was created), but we have to activate
1939 // the SATB queue if the thread is created while a marking cycle is
1940 // in progress. The activation / de-activation of the SATB queues at
1941 // the beginning / end of a marking cycle is done during safepoints
1942 // so we have to make sure this method is called outside one to be
1943 // able to safely read the active field of the SATB queue set. Right
1944 // now, it is called just before the thread is added to the Java
1945 // thread list in the Threads::add() method. That method is holding
1946 // the Threads_lock which ensures we are outside a safepoint. We
1947 // cannot do the obvious and set the active field of the SATB queue
1948 // when the thread is created given that, in some cases, safepoints
1949 // might happen between the JavaThread constructor being called and the
1950 // thread being added to the Java thread list (an example of this is
1951 // when the structure for the DestroyJavaVM thread is created).
1952 #if INCLUDE_ALL_GCS
1953 void initialize_queues();
1954 #else // INCLUDE_ALL_GCS
1955 void initialize_queues() { }
1956 #endif // INCLUDE_ALL_GCS
1957
1958 // Machine dependent stuff
1959 #include OS_CPU_HEADER(thread)
1960
1961 public:
1962 void set_blocked_on_compilation(bool value) {
1963 _blocked_on_compilation = value;
1964 }
1965
1966 bool blocked_on_compilation() {
1967 return _blocked_on_compilation;
1968 }
1969 protected:
1970 bool _blocked_on_compilation;
1971
1972
1973 // JSR166 per-thread parker
1974 private:
1975 Parker* _parker;
1976 public:
1977 Parker* parker() { return _parker; }
1978
1979 // Biased locking support
1980 private:
1981 GrowableArray<MonitorInfo*>* _cached_monitor_info;
1982 public:
1983 GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
1984 void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
1985
1986 // clearing/querying jni attach status
1987 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
1988 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
1989 inline void set_done_attaching_via_jni();
1990 };
1991
1992 // Inline implementation of JavaThread::current
1993 inline JavaThread* JavaThread::current() {
1994 Thread* thread = Thread::current();
1995 assert(thread->is_Java_thread(), "just checking");
1996 return (JavaThread*)thread;
1997 }
1998
1999 inline CompilerThread* JavaThread::as_CompilerThread() {
2000 assert(is_Compiler_thread(), "just checking");
2001 return (CompilerThread*)this;
2002 }
2003
2004 // Dedicated thread to sweep the code cache
2005 class CodeCacheSweeperThread : public JavaThread {
2006 CompiledMethod* _scanned_compiled_method; // nmethod being scanned by the sweeper
2007 public:
2008 CodeCacheSweeperThread();
2009 // Track the nmethod currently being scanned by the sweeper
2010 void set_scanned_compiled_method(CompiledMethod* cm) {
2011 assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value");
2012 _scanned_compiled_method = cm;
2013 }
2014
2015 // Hide sweeper thread from external view.
2016 bool is_hidden_from_external_view() const { return true; }
2017
2018 bool is_Code_cache_sweeper_thread() const { return true; }
2019
2020 // Prevent GC from unloading _scanned_compiled_method
2021 void oops_do(OopClosure* f, CodeBlobClosure* cf);
2022 void nmethods_do(CodeBlobClosure* cf);
2023 };
2024
2025 // A thread used for Compilation.
2026 class CompilerThread : public JavaThread {
2027 friend class VMStructs;
2028 private:
2029 CompilerCounters* _counters;
2030
2031 ciEnv* _env;
2032 CompileLog* _log;
2033 CompileTask* _task;
2034 CompileQueue* _queue;
2035 BufferBlob* _buffer_blob;
2036
2037 AbstractCompiler* _compiler;
2038
2039 public:
2040
2041 static CompilerThread* current();
2042
2043 CompilerThread(CompileQueue* queue, CompilerCounters* counters);
2044
2045 bool is_Compiler_thread() const { return true; }
2046
2047 virtual bool can_call_java() const;
2048
2049 // Hide native compiler threads from external view.
2050 bool is_hidden_from_external_view() const { return !can_call_java(); }
2051
2052 void set_compiler(AbstractCompiler* c) { _compiler = c; }
2053 AbstractCompiler* compiler() const { return _compiler; }
2054
2055 CompileQueue* queue() const { return _queue; }
2056 CompilerCounters* counters() const { return _counters; }
2057
2058 // Get/set the thread's compilation environment.
2059 ciEnv* env() { return _env; }
2060 void set_env(ciEnv* env) { _env = env; }
2061
2062 BufferBlob* get_buffer_blob() const { return _buffer_blob; }
2063 void set_buffer_blob(BufferBlob* b) { _buffer_blob = b; }
2064
2065 // Get/set the thread's logging information
2066 CompileLog* log() { return _log; }
2067 void init_log(CompileLog* log) {
2068 // Set once, for good.
2069 assert(_log == NULL, "set only once");
2070 _log = log;
2071 }
2072
2073 #ifndef PRODUCT
2074 private:
2075 IdealGraphPrinter *_ideal_graph_printer;
2076 public:
2077 IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; }
2078 void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2079 #endif
2080
2081 // Get/set the thread's current task
2082 CompileTask* task() { return _task; }
2083 void set_task(CompileTask* task) { _task = task; }
2084 };
2085
2086 inline CompilerThread* CompilerThread::current() {
2087 return JavaThread::current()->as_CompilerThread();
2088 }
2089
2090 // The active thread queue. It also keeps track of the current used
2091 // thread priorities.
2092 class Threads: AllStatic {
2093 friend class VMStructs;
2094 private:
2095 // Safe Memory Reclamation (SMR) support:
2096 static Monitor* _smr_delete_lock;
2097 // The '_cnt', '_max' and '_times" fields are enabled via
2098 // -XX:+EnableThreadSMRStatistics:
2099 static uint _smr_delete_lock_wait_cnt;
2100 static uint _smr_delete_lock_wait_max;
2101 static volatile int _smr_delete_notify;
2102 static volatile jint _smr_deleted_thread_cnt;
2103 static volatile jint _smr_deleted_thread_time_max;
2104 static volatile jint _smr_deleted_thread_times;
2105 static ThreadsList* volatile _smr_java_thread_list;
2106 static ThreadsList* get_smr_java_thread_list();
2107 static ThreadsList* xchg_smr_java_thread_list(ThreadsList* new_list);
2108 static long _smr_java_thread_list_alloc_cnt;
2109 static long _smr_java_thread_list_free_cnt;
2110 static uint _smr_java_thread_list_max;
2111 static uint _smr_nested_thread_list_max;
2112 static volatile jint _smr_tlh_cnt;
2113 static volatile jint _smr_tlh_time_max;
2114 static volatile jint _smr_tlh_times;
2115 static ThreadsList* _smr_to_delete_list;
2116 static uint _smr_to_delete_list_cnt;
2117 static uint _smr_to_delete_list_max;
2118
2119 static JavaThread* _thread_list;
2120 static int _number_of_threads;
2121 static int _number_of_non_daemon_threads;
2122 static int _return_code;
2123 static int _thread_claim_parity;
2124 #ifdef ASSERT
2125 static bool _vm_complete;
2126 #endif
2127
2128 static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2129 static void initialize_jsr292_core_classes(TRAPS);
2130
2131 static void smr_free_list(ThreadsList* threads);
2132
2133 public:
2134 // Thread management
2135 // force_daemon is a concession to JNI, where we may need to add a
2136 // thread to the thread list before allocating its thread object
2137 static void add(JavaThread* p, bool force_daemon = false);
2138 static void remove(JavaThread* p);
2139 static void threads_do(ThreadClosure* tc);
2140 static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
2141
2142 // SMR support:
2143 template <class T>
2144 static void threads_do_smr(T *tc, Thread *self);
2145 static ThreadsList *acquire_stable_list(Thread *self, bool is_ThreadsListSetter);
2146 static ThreadsList *acquire_stable_list_fast_path(Thread *self);
2147 static ThreadsList *acquire_stable_list_nested_path(Thread *self);
2148 static void release_stable_list(Thread *self);
2149 static void release_stable_list_fast_path(Thread *self);
2150 static void release_stable_list_nested_path(Thread *self);
2151 static void release_stable_list_wake_up(char *log_str);
2152 static bool is_a_protected_JavaThread(JavaThread *thread);
2153 static bool is_a_protected_JavaThread_with_lock(JavaThread *thread) {
2154 MutexLockerEx ml(Threads_lock->owned_by_self() ? NULL : Threads_lock);
2155 return is_a_protected_JavaThread(thread);
2156 }
2157 static void smr_delete(JavaThread *thread);
2158 // The coordination between Threads::release_stable_list() and
2159 // Threads::smr_delete() uses the smr_delete_lock in order to
2160 // reduce the traffic on the Threads_lock.
2161 static Monitor* smr_delete_lock() { return _smr_delete_lock; }
2162 // The smr_delete_notify flag is used for proper double-check
2163 // locking in order to reduce the traffic on the smr_delete_lock.
2164 static bool smr_delete_notify();
2165 static void set_smr_delete_notify();
2166 static void clear_smr_delete_notify();
2167 static void inc_smr_deleted_thread_cnt();
2168 static void update_smr_deleted_thread_time_max(jint new_value);
2169 static void add_smr_deleted_thread_times(jint add_value);
2170 static void inc_smr_tlh_cnt();
2171 static void update_smr_tlh_time_max(jint new_value);
2172 static void add_smr_tlh_times(jint add_value);
2173
2174 // Initializes the vm and creates the vm thread
2175 static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
2176 static void convert_vm_init_libraries_to_agents();
2177 static void create_vm_init_libraries();
2178 static void create_vm_init_agents();
2179 static void shutdown_vm_agents();
2180 static bool destroy_vm();
2181 // Supported VM versions via JNI
2182 // Includes JNI_VERSION_1_1
2183 static jboolean is_supported_jni_version_including_1_1(jint version);
2184 // Does not include JNI_VERSION_1_1
2185 static jboolean is_supported_jni_version(jint version);
2186
2187 // The "thread claim parity" provides a way for threads to be claimed
2188 // by parallel worker tasks.
2189 //
2190 // Each thread contains a a "parity" field. A task will claim the
2191 // thread only if its parity field is the same as the global parity,
2192 // which is updated by calling change_thread_claim_parity().
2193 //
2194 // For this to work change_thread_claim_parity() needs to be called
2195 // exactly once in sequential code before starting parallel tasks
2196 // that should claim threads.
2197 //
2198 // New threads get their parity set to 0 and change_thread_claim_parity()
2199 // never set the global parity to 0.
2200 static int thread_claim_parity() { return _thread_claim_parity; }
2201 static void change_thread_claim_parity();
2202 static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
2203
2204 // Apply "f->do_oop" to all root oops in all threads.
2205 // This version may only be called by sequential code.
2206 static void oops_do(OopClosure* f, CodeBlobClosure* cf);
2207 // This version may be called by sequential or parallel code.
2208 static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
2209 // This creates a list of GCTasks, one per thread.
2210 static void create_thread_roots_tasks(GCTaskQueue* q);
2211 // This creates a list of GCTasks, one per thread, for marking objects.
2212 static void create_thread_roots_marking_tasks(GCTaskQueue* q);
2213
2214 // Apply "f->do_oop" to roots in all threads that
2215 // are part of compiled frames
2216 static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf);
2217
2218 static void convert_hcode_pointers();
2219 static void restore_hcode_pointers();
2220
2221 // Sweeper
2222 static void nmethods_do(CodeBlobClosure* cf);
2223
2224 // RedefineClasses support
2225 static void metadata_do(void f(Metadata*));
2226 static void metadata_handles_do(void f(Metadata*));
2227
2228 #ifdef ASSERT
2229 static bool is_vm_complete() { return _vm_complete; }
2230 #endif
2231
2232 // Verification
2233 static void verify();
2234 static void log_smr_statistics();
2235 static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks);
2236 static void print_smr_info_on(outputStream* st);
2237 static void print_smr_info_elements_on(outputStream* st, ThreadsList* t_list);
2238 static void print(bool print_stacks, bool internal_format) {
2239 // this function is only used by debug.cpp
2240 print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */);
2241 }
2242 static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2243 static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
2244 int buflen, bool* found_current);
2245 static void print_threads_compiling(outputStream* st, char* buf, int buflen);
2246
2247 // Get Java threads that are waiting to enter a monitor.
2248 static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
2249 int count, address monitor);
2250
2251 // Get owning Java thread from the monitor's owner field.
2252 static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
2253 address owner);
2254
2255 // Number of threads on the active threads list
2256 static int number_of_threads() { return _number_of_threads; }
2257 // Number of non-daemon threads on the active threads list
2258 static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; }
2259
2260 // Deoptimizes all frames tied to marked nmethods
2261 static void deoptimized_wrt_marked_nmethods();
2262 };
2263
2264
2265 // Thread iterator
2266 class ThreadClosure: public StackObj {
2267 public:
2268 virtual void do_thread(Thread* thread) = 0;
2269 };
2270
2271 class SignalHandlerMark: public StackObj {
2272 private:
2273 Thread* _thread;
2274 public:
2275 SignalHandlerMark(Thread* t) {
2276 _thread = t;
2277 if (_thread) _thread->enter_signal_handler();
2278 }
2279 ~SignalHandlerMark() {
2280 if (_thread) _thread->leave_signal_handler();
2281 _thread = NULL;
2282 }
2283 };
2284
2285
2286 #endif // SHARE_VM_RUNTIME_THREAD_HPP