1 /*
2 * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_VM_RUNTIME_THREAD_HPP
26 #define SHARE_VM_RUNTIME_THREAD_HPP
27
28 #include "jni.h"
29 #include "gc/shared/gcThreadLocalData.hpp"
30 #include "gc/shared/threadLocalAllocBuffer.hpp"
31 #include "memory/allocation.hpp"
32 #include "oops/oop.hpp"
33 #include "prims/jvmtiExport.hpp"
34 #include "runtime/frame.hpp"
35 #include "runtime/globals.hpp"
36 #include "runtime/handshake.hpp"
37 #include "runtime/javaFrameAnchor.hpp"
38 #include "runtime/jniHandles.hpp"
39 #include "runtime/mutexLocker.hpp"
40 #include "runtime/os.hpp"
41 #include "runtime/osThread.hpp"
42 #include "runtime/park.hpp"
43 #include "runtime/safepoint.hpp"
44 #include "runtime/stubRoutines.hpp"
45 #include "runtime/threadHeapSampler.hpp"
46 #include "runtime/threadLocalStorage.hpp"
47 #include "runtime/threadStatisticalInfo.hpp"
48 #include "runtime/unhandledOops.hpp"
49 #include "utilities/align.hpp"
50 #include "utilities/exceptions.hpp"
51 #include "utilities/macros.hpp"
52 #ifdef ZERO
53 # include "stack_zero.hpp"
54 #endif
55 #if INCLUDE_JFR
56 #include "jfr/support/jfrThreadExtension.hpp"
57 #endif
58
59
60 class SafeThreadsListPtr;
61 class ThreadSafepointState;
62 class ThreadsList;
63 class ThreadsSMRSupport;
64
65 class JvmtiThreadState;
66 class ThreadStatistics;
67 class ConcurrentLocksDump;
68 class ParkEvent;
69 class Parker;
70
71 class ciEnv;
72 class CompileThread;
73 class CompileLog;
74 class CompileTask;
75 class CompileQueue;
76 class CompilerCounters;
77 class vframeArray;
78
79 class DeoptResourceMark;
80 class jvmtiDeferredLocalVariableSet;
81
82 class GCTaskQueue;
83 class ThreadClosure;
84 class IdealGraphPrinter;
85
86 class Metadata;
87 template <class T, MEMFLAGS F> class ChunkedList;
88 typedef ChunkedList<Metadata*, mtInternal> MetadataOnStackBuffer;
89
90 DEBUG_ONLY(class ResourceMark;)
91
92 class WorkerThread;
93
94 // Class hierarchy
95 // - Thread
96 // - JavaThread
97 // - various subclasses eg CompilerThread, ServiceThread
98 // - NonJavaThread
99 // - NamedThread
100 // - VMThread
101 // - ConcurrentGCThread
102 // - WorkerThread
103 // - GangWorker
104 // - GCTaskThread
105 // - WatcherThread
106 // - JfrThreadSampler
107 //
108 // All Thread subclasses must be either JavaThread or NonJavaThread.
109 // This means !t->is_Java_thread() iff t is a NonJavaThread, or t is
110 // a partially constructed/destroyed Thread.
111
112 class Thread: public ThreadShadow {
113 friend class VMStructs;
114 friend class JVMCIVMStructs;
115 private:
116
117 #ifndef USE_LIBRARY_BASED_TLS_ONLY
118 // Current thread is maintained as a thread-local variable
119 static THREAD_LOCAL_DECL Thread* _thr_current;
120 #endif
121
122 private:
123 // Thread local data area available to the GC. The internal
124 // structure and contents of this data area is GC-specific.
125 // Only GC and GC barrier code should access this data area.
126 GCThreadLocalData _gc_data;
127
128 public:
129 static ByteSize gc_data_offset() {
130 return byte_offset_of(Thread, _gc_data);
131 }
132
133 template <typename T> T* gc_data() {
134 STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data));
135 return reinterpret_cast<T*>(&_gc_data);
136 }
137
138 // Exception handling
139 // (Note: _pending_exception and friends are in ThreadShadow)
140 //oop _pending_exception; // pending exception for current thread
141 // const char* _exception_file; // file information for exception (debugging only)
142 // int _exception_line; // line information for exception (debugging only)
143 protected:
144 // Support for forcing alignment of thread objects for biased locking
145 void* _real_malloc_address;
146
147 // JavaThread lifecycle support:
148 friend class SafeThreadsListPtr; // for _threads_list_ptr, cmpxchg_threads_hazard_ptr(), {dec_,inc_,}nested_threads_hazard_ptr_cnt(), {g,s}et_threads_hazard_ptr(), inc_nested_handle_cnt(), tag_hazard_ptr() access
149 friend class ScanHazardPtrGatherProtectedThreadsClosure; // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
150 friend class ScanHazardPtrGatherThreadsListClosure; // for get_threads_hazard_ptr(), untag_hazard_ptr() access
151 friend class ScanHazardPtrPrintMatchingThreadsClosure; // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
152 friend class ThreadsSMRSupport; // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
153
154 ThreadsList* volatile _threads_hazard_ptr;
155 SafeThreadsListPtr* _threads_list_ptr;
156 ThreadsList* cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
157 ThreadsList* get_threads_hazard_ptr();
158 void set_threads_hazard_ptr(ThreadsList* new_list);
159 static bool is_hazard_ptr_tagged(ThreadsList* list) {
160 return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
161 }
162 static ThreadsList* tag_hazard_ptr(ThreadsList* list) {
163 return (ThreadsList*)(intptr_t(list) | intptr_t(1));
164 }
165 static ThreadsList* untag_hazard_ptr(ThreadsList* list) {
166 return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
167 }
168 // This field is enabled via -XX:+EnableThreadSMRStatistics:
169 uint _nested_threads_hazard_ptr_cnt;
170 void dec_nested_threads_hazard_ptr_cnt() {
171 assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
172 _nested_threads_hazard_ptr_cnt--;
173 }
174 void inc_nested_threads_hazard_ptr_cnt() {
175 _nested_threads_hazard_ptr_cnt++;
176 }
177 uint nested_threads_hazard_ptr_cnt() {
178 return _nested_threads_hazard_ptr_cnt;
179 }
180
181 public:
182 void* operator new(size_t size) throw() { return allocate(size, true); }
183 void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
184 return allocate(size, false); }
185 void operator delete(void* p);
186
187 protected:
188 static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
189 private:
190
191 // ***************************************************************
192 // Suspend and resume support
193 // ***************************************************************
194 //
195 // VM suspend/resume no longer exists - it was once used for various
196 // things including safepoints but was deprecated and finally removed
197 // in Java 7. Because VM suspension was considered "internal" Java-level
198 // suspension was considered "external", and this legacy naming scheme
199 // remains.
200 //
201 // External suspend/resume requests come from JVM_SuspendThread,
202 // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
203 // ResumeThread. External
204 // suspend requests cause _external_suspend to be set and external
205 // resume requests cause _external_suspend to be cleared.
206 // External suspend requests do not nest on top of other external
207 // suspend requests. The higher level APIs reject suspend requests
208 // for already suspended threads.
209 //
210 // The external_suspend
211 // flag is checked by has_special_runtime_exit_condition() and java thread
212 // will self-suspend when handle_special_runtime_exit_condition() is
213 // called. Most uses of the _thread_blocked state in JavaThreads are
214 // considered the same as being externally suspended; if the blocking
215 // condition lifts, the JavaThread will self-suspend. Other places
216 // where VM checks for external_suspend include:
217 // + mutex granting (do not enter monitors when thread is suspended)
218 // + state transitions from _thread_in_native
219 //
220 // In general, java_suspend() does not wait for an external suspend
221 // request to complete. When it returns, the only guarantee is that
222 // the _external_suspend field is true.
223 //
224 // wait_for_ext_suspend_completion() is used to wait for an external
225 // suspend request to complete. External suspend requests are usually
226 // followed by some other interface call that requires the thread to
227 // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
228 // the interface that requires quiescence, we give the JavaThread a
229 // chance to self-suspend before we need it to be quiescent. This
230 // improves overall suspend/query performance.
231 //
232 // _suspend_flags controls the behavior of java_ suspend/resume.
233 // It must be set under the protection of SR_lock. Read from the flag is
234 // OK without SR_lock as long as the value is only used as a hint.
235 // (e.g., check _external_suspend first without lock and then recheck
236 // inside SR_lock and finish the suspension)
237 //
238 // _suspend_flags is also overloaded for other "special conditions" so
239 // that a single check indicates whether any special action is needed
240 // eg. for async exceptions.
241 // -------------------------------------------------------------------
242 // Notes:
243 // 1. The suspend/resume logic no longer uses ThreadState in OSThread
244 // but we still update its value to keep other part of the system (mainly
245 // JVMTI) happy. ThreadState is legacy code (see notes in
246 // osThread.hpp).
247 //
248 // 2. It would be more natural if set_external_suspend() is private and
249 // part of java_suspend(), but that probably would affect the suspend/query
250 // performance. Need more investigation on this.
251
252 // suspend/resume lock: used for self-suspend
253 Monitor* _SR_lock;
254
255 protected:
256 enum SuspendFlags {
257 // NOTE: avoid using the sign-bit as cc generates different test code
258 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
259
260 _external_suspend = 0x20000000U, // thread is asked to self suspend
261 _ext_suspended = 0x40000000U, // thread has self-suspended
262 _deopt_suspend = 0x10000000U, // thread needs to self suspend for deopt
263
264 _has_async_exception = 0x00000001U, // there is a pending async exception
265 _critical_native_unlock = 0x00000002U, // Must call back to unlock JNI critical lock
266
267 _trace_flag = 0x00000004U // call tracing backend
268 };
269
270 // various suspension related flags - atomically updated
271 // overloaded for async exception checking in check_special_condition_for_native_trans.
272 volatile uint32_t _suspend_flags;
273
274 private:
275 int _num_nested_signal;
276
277 DEBUG_ONLY(bool _suspendible_thread;)
278
279 public:
280 void enter_signal_handler() { _num_nested_signal++; }
281 void leave_signal_handler() { _num_nested_signal--; }
282 bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
283
284 #ifdef ASSERT
285 void set_suspendible_thread() {
286 _suspendible_thread = true;
287 }
288
289 void clear_suspendible_thread() {
290 _suspendible_thread = false;
291 }
292
293 bool is_suspendible_thread() { return _suspendible_thread; }
294 #endif
295
296 private:
297 // Active_handles points to a block of handles
298 JNIHandleBlock* _active_handles;
299
300 // One-element thread local free list
301 JNIHandleBlock* _free_handle_block;
302
303 // Point to the last handle mark
304 HandleMark* _last_handle_mark;
305
306 // The parity of the last strong_roots iteration in which this thread was
307 // claimed as a task.
308 int _oops_do_parity;
309
310 // Support for GlobalCounter
311 private:
312 volatile uintx _rcu_counter;
313 public:
314 volatile uintx* get_rcu_counter() {
315 return &_rcu_counter;
316 }
317
318 public:
319 void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; }
320 HandleMark* last_handle_mark() const { return _last_handle_mark; }
321 private:
322
323 // debug support for checking if code does allow safepoints or not
324 // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on
325 // mutex, or blocking on an object synchronizer (Java locking).
326 // If !allow_safepoint(), then an assertion failure will happen in any of the above cases
327 // If !allow_allocation(), then an assertion failure will happen during allocation
328 // (Hence, !allow_safepoint() => !allow_allocation()).
329 //
330 // The two classes NoSafepointVerifier and No_Allocation_Verifier are used to set these counters.
331 //
332 NOT_PRODUCT(int _allow_safepoint_count;) // If 0, thread allow a safepoint to happen
333 debug_only(int _allow_allocation_count;) // If 0, the thread is allowed to allocate oops.
334
335 // Used by SkipGCALot class.
336 NOT_PRODUCT(bool _skip_gcalot;) // Should we elide gc-a-lot?
337
338 friend class NoAllocVerifier;
339 friend class NoSafepointVerifier;
340 friend class PauseNoSafepointVerifier;
341 friend class GCLocker;
342
343 volatile void* _polling_page; // Thread local polling page
344
345 ThreadLocalAllocBuffer _tlab; // Thread-local eden
346 jlong _allocated_bytes; // Cumulative number of bytes allocated on
347 // the Java heap
348 ThreadHeapSampler _heap_sampler; // For use when sampling the memory.
349
350 ThreadStatisticalInfo _statistical_info; // Statistics about the thread
351
352 JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;) // Thread-local data for jfr
353
354 int _vm_operation_started_count; // VM_Operation support
355 int _vm_operation_completed_count; // VM_Operation support
356
357 ObjectMonitor* _current_pending_monitor; // ObjectMonitor this thread
358 // is waiting to lock
359 bool _current_pending_monitor_is_from_java; // locking is from Java code
360
361 // ObjectMonitor on which this thread called Object.wait()
362 ObjectMonitor* _current_waiting_monitor;
363
364 // Private thread-local objectmonitor list - a simple cache organized as a SLL.
365 public:
366 ObjectMonitor* omFreeList;
367 int omFreeCount; // length of omFreeList
368 int omFreeProvision; // reload chunk size
369 ObjectMonitor* omInUseList; // SLL to track monitors in circulation
370 int omInUseCount; // length of omInUseList
371
372 #ifdef ASSERT
373 private:
374 bool _visited_for_critical_count;
375
376 public:
377 void set_visited_for_critical_count(bool z) { _visited_for_critical_count = z; }
378 bool was_visited_for_critical_count() const { return _visited_for_critical_count; }
379 #endif
380
381 public:
382 enum {
383 is_definitely_current_thread = true
384 };
385
386 public:
387 // Constructor
388 Thread();
389 virtual ~Thread() = 0; // Thread is abstract.
390
391 // Manage Thread::current()
392 void initialize_thread_current();
393 void clear_thread_current(); // TLS cleanup needed before threads terminate
394
395 public:
396 // thread entry point
397 virtual void run();
398
399 // Testers
400 virtual bool is_VM_thread() const { return false; }
401 virtual bool is_Java_thread() const { return false; }
402 virtual bool is_Compiler_thread() const { return false; }
403 virtual bool is_Code_cache_sweeper_thread() const { return false; }
404 virtual bool is_hidden_from_external_view() const { return false; }
405 virtual bool is_jvmti_agent_thread() const { return false; }
406 // True iff the thread can perform GC operations at a safepoint.
407 // Generally will be true only of VM thread and parallel GC WorkGang
408 // threads.
409 virtual bool is_GC_task_thread() const { return false; }
410 virtual bool is_Watcher_thread() const { return false; }
411 virtual bool is_ConcurrentGC_thread() const { return false; }
412 virtual bool is_Named_thread() const { return false; }
413 virtual bool is_Worker_thread() const { return false; }
414
415 // Can this thread make Java upcalls
416 virtual bool can_call_java() const { return false; }
417
418 // Casts
419 virtual WorkerThread* as_Worker_thread() const { return NULL; }
420
421 virtual char* name() const { return (char*)"Unknown thread"; }
422
423 // Returns the current thread (ASSERTS if NULL)
424 static inline Thread* current();
425 // Returns the current thread, or NULL if not attached
426 static inline Thread* current_or_null();
427 // Returns the current thread, or NULL if not attached, and is
428 // safe for use from signal-handlers
429 static inline Thread* current_or_null_safe();
430
431 // Common thread operations
432 #ifdef ASSERT
433 static void check_for_dangling_thread_pointer(Thread *thread);
434 #endif
435 static void set_priority(Thread* thread, ThreadPriority priority);
436 static ThreadPriority get_priority(const Thread* const thread);
437 static void start(Thread* thread);
438 static void interrupt(Thread* thr);
439 static bool is_interrupted(Thread* thr, bool clear_interrupted);
440
441 void set_native_thread_name(const char *name) {
442 assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
443 os::set_native_thread_name(name);
444 }
445
446 ObjectMonitor** omInUseList_addr() { return (ObjectMonitor **)&omInUseList; }
447 Monitor* SR_lock() const { return _SR_lock; }
448
449 bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
450
451 inline void set_suspend_flag(SuspendFlags f);
452 inline void clear_suspend_flag(SuspendFlags f);
453
454 inline void set_has_async_exception();
455 inline void clear_has_async_exception();
456
457 bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
458
459 inline void set_critical_native_unlock();
460 inline void clear_critical_native_unlock();
461
462 inline void set_trace_flag();
463 inline void clear_trace_flag();
464
465 // Support for Unhandled Oop detection
466 // Add the field for both, fastdebug and debug, builds to keep
467 // Thread's fields layout the same.
468 // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
469 #ifdef CHECK_UNHANDLED_OOPS
470 private:
471 UnhandledOops* _unhandled_oops;
472 #elif defined(ASSERT)
473 private:
474 void* _unhandled_oops;
475 #endif
476 #ifdef CHECK_UNHANDLED_OOPS
477 public:
478 UnhandledOops* unhandled_oops() { return _unhandled_oops; }
479 // Mark oop safe for gc. It may be stack allocated but won't move.
480 void allow_unhandled_oop(oop *op) {
481 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
482 }
483 // Clear oops at safepoint so crashes point to unhandled oop violator
484 void clear_unhandled_oops() {
485 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
486 }
487 #endif // CHECK_UNHANDLED_OOPS
488
489 public:
490 #ifndef PRODUCT
491 bool skip_gcalot() { return _skip_gcalot; }
492 void set_skip_gcalot(bool v) { _skip_gcalot = v; }
493 #endif
494
495 // Installs a pending exception to be inserted later
496 static void send_async_exception(oop thread_oop, oop java_throwable);
497
498 // Resource area
499 ResourceArea* resource_area() const { return _resource_area; }
500 void set_resource_area(ResourceArea* area) { _resource_area = area; }
501
502 OSThread* osthread() const { return _osthread; }
503 void set_osthread(OSThread* thread) { _osthread = thread; }
504
505 // JNI handle support
506 JNIHandleBlock* active_handles() const { return _active_handles; }
507 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
508 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
509 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
510
511 // Internal handle support
512 HandleArea* handle_area() const { return _handle_area; }
513 void set_handle_area(HandleArea* area) { _handle_area = area; }
514
515 GrowableArray<Metadata*>* metadata_handles() const { return _metadata_handles; }
516 void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
517
518 // Thread-Local Allocation Buffer (TLAB) support
519 ThreadLocalAllocBuffer& tlab() { return _tlab; }
520 void initialize_tlab() {
521 if (UseTLAB) {
522 tlab().initialize();
523 }
524 }
525
526 jlong allocated_bytes() { return _allocated_bytes; }
527 void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
528 void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
529 inline jlong cooked_allocated_bytes();
530
531 ThreadHeapSampler& heap_sampler() { return _heap_sampler; }
532
533 ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
534
535 JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
536
537 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; }
538
539 // VM operation support
540 int vm_operation_ticket() { return ++_vm_operation_started_count; }
541 int vm_operation_completed_count() { return _vm_operation_completed_count; }
542 void increment_vm_operation_completed_count() { _vm_operation_completed_count++; }
543
544 // For tracking the heavyweight monitor the thread is pending on.
545 ObjectMonitor* current_pending_monitor() {
546 return _current_pending_monitor;
547 }
548 void set_current_pending_monitor(ObjectMonitor* monitor) {
549 _current_pending_monitor = monitor;
550 }
551 void set_current_pending_monitor_is_from_java(bool from_java) {
552 _current_pending_monitor_is_from_java = from_java;
553 }
554 bool current_pending_monitor_is_from_java() {
555 return _current_pending_monitor_is_from_java;
556 }
557
558 // For tracking the ObjectMonitor on which this thread called Object.wait()
559 ObjectMonitor* current_waiting_monitor() {
560 return _current_waiting_monitor;
561 }
562 void set_current_waiting_monitor(ObjectMonitor* monitor) {
563 _current_waiting_monitor = monitor;
564 }
565
566 // GC support
567 // Apply "f->do_oop" to all root oops in "this".
568 // Used by JavaThread::oops_do.
569 // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
570 virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
571
572 // Handles the parallel case for the method below.
573 private:
574 bool claim_oops_do_par_case(int collection_parity);
575 public:
576 // Requires that "collection_parity" is that of the current roots
577 // iteration. If "is_par" is false, sets the parity of "this" to
578 // "collection_parity", and returns "true". If "is_par" is true,
579 // uses an atomic instruction to set the current threads parity to
580 // "collection_parity", if it is not already. Returns "true" iff the
581 // calling thread does the update, this indicates that the calling thread
582 // has claimed the thread's stack as a root groop in the current
583 // collection.
584 bool claim_oops_do(bool is_par, int collection_parity) {
585 if (!is_par) {
586 _oops_do_parity = collection_parity;
587 return true;
588 } else {
589 return claim_oops_do_par_case(collection_parity);
590 }
591 }
592
593 // jvmtiRedefineClasses support
594 void metadata_handles_do(void f(Metadata*));
595
596 // Used by fast lock support
597 virtual bool is_lock_owned(address adr) const;
598
599 // Check if address is in the stack of the thread (not just for locks).
600 // Warning: the method can only be used on the running thread
601 bool is_in_stack(address adr) const;
602 // Check if address is in the usable part of the stack (excludes protected
603 // guard pages)
604 bool is_in_usable_stack(address adr) const;
605
606 // Sets this thread as starting thread. Returns failure if thread
607 // creation fails due to lack of memory, too many threads etc.
608 bool set_as_starting_thread();
609
610 protected:
611 // OS data associated with the thread
612 OSThread* _osthread; // Platform-specific thread information
613
614 // Thread local resource area for temporary allocation within the VM
615 ResourceArea* _resource_area;
616
617 DEBUG_ONLY(ResourceMark* _current_resource_mark;)
618
619 // Thread local handle area for allocation of handles within the VM
620 HandleArea* _handle_area;
621 GrowableArray<Metadata*>* _metadata_handles;
622
623 // Support for stack overflow handling, get_thread, etc.
624 address _stack_base;
625 size_t _stack_size;
626 uintptr_t _self_raw_id; // used by get_thread (mutable)
627 int _lgrp_id;
628
629 volatile void** polling_page_addr() { return &_polling_page; }
630
631 public:
632 // Stack overflow support
633 address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
634 void set_stack_base(address base) { _stack_base = base; }
635 size_t stack_size() const { return _stack_size; }
636 void set_stack_size(size_t size) { _stack_size = size; }
637 address stack_end() const { return stack_base() - stack_size(); }
638 void record_stack_base_and_size();
639
640 bool on_local_stack(address adr) const {
641 // QQQ this has knowledge of direction, ought to be a stack method
642 return (_stack_base >= adr && adr >= stack_end());
643 }
644
645 uintptr_t self_raw_id() { return _self_raw_id; }
646 void set_self_raw_id(uintptr_t value) { _self_raw_id = value; }
647
648 int lgrp_id() const { return _lgrp_id; }
649 void set_lgrp_id(int value) { _lgrp_id = value; }
650
651 // Printing
652 void print_on(outputStream* st, bool print_extended_info) const;
653 virtual void print_on(outputStream* st) const { print_on(st, false); }
654 void print() const { print_on(tty); }
655 virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
656 void print_value_on(outputStream* st) const;
657
658 // Debug-only code
659 #ifdef ASSERT
660 private:
661 // Deadlock detection support for Mutex locks. List of locks own by thread.
662 Monitor* _owned_locks;
663 // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
664 // thus the friendship
665 friend class Mutex;
666 friend class Monitor;
667
668 public:
669 void print_owned_locks_on(outputStream* st) const;
670 void print_owned_locks() const { print_owned_locks_on(tty); }
671 Monitor* owned_locks() const { return _owned_locks; }
672 bool owns_locks() const { return owned_locks() != NULL; }
673 bool owns_locks_but_compiled_lock() const;
674 int oops_do_parity() const { return _oops_do_parity; }
675
676 // Deadlock detection
677 bool allow_allocation() { return _allow_allocation_count == 0; }
678 ResourceMark* current_resource_mark() { return _current_resource_mark; }
679 void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
680 #endif
681
682 void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN;
683
684 private:
685 volatile int _jvmti_env_iteration_count;
686
687 public:
688 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; }
689 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; }
690 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; }
691
692 // Code generation
693 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file); }
694 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line); }
695 static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles); }
696
697 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base); }
698 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size); }
699
700 static ByteSize polling_page_offset() { return byte_offset_of(Thread, _polling_page); }
701
702 #define TLAB_FIELD_OFFSET(name) \
703 static ByteSize tlab_##name##_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::name##_offset(); }
704
705 TLAB_FIELD_OFFSET(start)
706 TLAB_FIELD_OFFSET(end)
707 TLAB_FIELD_OFFSET(top)
708 TLAB_FIELD_OFFSET(pf_top)
709 TLAB_FIELD_OFFSET(size) // desired_size
710 TLAB_FIELD_OFFSET(refill_waste_limit)
711 TLAB_FIELD_OFFSET(number_of_refills)
712 TLAB_FIELD_OFFSET(fast_refill_waste)
713 TLAB_FIELD_OFFSET(slow_allocations)
714
715 #undef TLAB_FIELD_OFFSET
716
717 static ByteSize allocated_bytes_offset() { return byte_offset_of(Thread, _allocated_bytes); }
718
719 JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
720
721 public:
722 volatile intptr_t _Stalled;
723 volatile int _TypeTag;
724 ParkEvent * _ParkEvent; // for synchronized()
725 ParkEvent * _SleepEvent; // for Thread.sleep
726 ParkEvent * _MutexEvent; // for native internal Mutex/Monitor
727 ParkEvent * _MuxEvent; // for low-level muxAcquire-muxRelease
728 int NativeSyncRecursion; // diagnostic
729
730 volatile int _OnTrap; // Resume-at IP delta
731 jint _hashStateW; // Marsaglia Shift-XOR thread-local RNG
732 jint _hashStateX; // thread-specific hashCode generator state
733 jint _hashStateY;
734 jint _hashStateZ;
735
736 volatile jint rng[4]; // RNG for spin loop
737
738 // Low-level leaf-lock primitives used to implement synchronization
739 // and native monitor-mutex infrastructure.
740 // Not for general synchronization use.
741 static void SpinAcquire(volatile int * Lock, const char * Name);
742 static void SpinRelease(volatile int * Lock);
743 static void muxAcquire(volatile intptr_t * Lock, const char * Name);
744 static void muxAcquireW(volatile intptr_t * Lock, ParkEvent * ev);
745 static void muxRelease(volatile intptr_t * Lock);
746 };
747
748 // Inline implementation of Thread::current()
749 inline Thread* Thread::current() {
750 Thread* current = current_or_null();
751 assert(current != NULL, "Thread::current() called on detached thread");
752 return current;
753 }
754
755 inline Thread* Thread::current_or_null() {
756 #ifndef USE_LIBRARY_BASED_TLS_ONLY
757 return _thr_current;
758 #else
759 if (ThreadLocalStorage::is_initialized()) {
760 return ThreadLocalStorage::thread();
761 }
762 return NULL;
763 #endif
764 }
765
766 inline Thread* Thread::current_or_null_safe() {
767 if (ThreadLocalStorage::is_initialized()) {
768 return ThreadLocalStorage::thread();
769 }
770 return NULL;
771 }
772
773 class NonJavaThread: public Thread {
774 friend class VMStructs;
775
776 NonJavaThread* volatile _next;
777
778 class List;
779 static List _the_list;
780
781 public:
782 NonJavaThread();
783 ~NonJavaThread();
784
785 class Iterator;
786 };
787
788 // Provides iteration over the list of NonJavaThreads. Because list
789 // management occurs in the NonJavaThread constructor and destructor,
790 // entries in the list may not be fully constructed instances of a
791 // derived class. Threads created after an iterator is constructed
792 // will not be visited by the iterator. The scope of an iterator is a
793 // critical section; there must be no safepoint checks in that scope.
794 class NonJavaThread::Iterator : public StackObj {
795 uint _protect_enter;
796 NonJavaThread* _current;
797
798 // Noncopyable.
799 Iterator(const Iterator&);
800 Iterator& operator=(const Iterator&);
801
802 public:
803 Iterator();
804 ~Iterator();
805
806 bool end() const { return _current == NULL; }
807 NonJavaThread* current() const { return _current; }
808 void step();
809 };
810
811 // Name support for threads. non-JavaThread subclasses with multiple
812 // uniquely named instances should derive from this.
813 class NamedThread: public NonJavaThread {
814 friend class VMStructs;
815 enum {
816 max_name_len = 64
817 };
818 private:
819 char* _name;
820 // log JavaThread being processed by oops_do
821 JavaThread* _processed_thread;
822 uint _gc_id; // The current GC id when a thread takes part in GC
823
824 public:
825 NamedThread();
826 ~NamedThread();
827 // May only be called once per thread.
828 void set_name(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
829 void initialize_named_thread();
830 virtual bool is_Named_thread() const { return true; }
831 virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
832 JavaThread *processed_thread() { return _processed_thread; }
833 void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
834 virtual void print_on(outputStream* st) const;
835
836 void set_gc_id(uint gc_id) { _gc_id = gc_id; }
837 uint gc_id() { return _gc_id; }
838 };
839
840 // Worker threads are named and have an id of an assigned work.
841 class WorkerThread: public NamedThread {
842 private:
843 uint _id;
844 public:
845 WorkerThread() : _id(0) { }
846 virtual bool is_Worker_thread() const { return true; }
847
848 virtual WorkerThread* as_Worker_thread() const {
849 assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
850 return (WorkerThread*) this;
851 }
852
853 void set_id(uint work_id) { _id = work_id; }
854 uint id() const { return _id; }
855 };
856
857 // A single WatcherThread is used for simulating timer interrupts.
858 class WatcherThread: public NonJavaThread {
859 friend class VMStructs;
860 public:
861 virtual void run();
862
863 private:
864 static WatcherThread* _watcher_thread;
865
866 static bool _startable;
867 // volatile due to at least one lock-free read
868 volatile static bool _should_terminate;
869 public:
870 enum SomeConstants {
871 delay_interval = 10 // interrupt delay in milliseconds
872 };
873
874 // Constructor
875 WatcherThread();
876
877 // No destruction allowed
878 ~WatcherThread() {
879 guarantee(false, "WatcherThread deletion must fix the race with VM termination");
880 }
881
882 // Tester
883 bool is_Watcher_thread() const { return true; }
884
885 // Printing
886 char* name() const { return (char*)"VM Periodic Task Thread"; }
887 void print_on(outputStream* st) const;
888 void unpark();
889
890 // Returns the single instance of WatcherThread
891 static WatcherThread* watcher_thread() { return _watcher_thread; }
892
893 // Create and start the single instance of WatcherThread, or stop it on shutdown
894 static void start();
895 static void stop();
896 // Only allow start once the VM is sufficiently initialized
897 // Otherwise the first task to enroll will trigger the start
898 static void make_startable();
899 private:
900 int sleep() const;
901 };
902
903
904 class CompilerThread;
905
906 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
907
908 class JavaThread: public Thread {
909 friend class VMStructs;
910 friend class JVMCIVMStructs;
911 friend class WhiteBox;
912 friend class VTBuffer;
913 private:
914 JavaThread* _next; // The next thread in the Threads list
915 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
916 oop _threadObj; // The Java level thread object
917
918 #ifdef ASSERT
919 private:
920 int _java_call_counter;
921
922 public:
923 int java_call_counter() { return _java_call_counter; }
924 void inc_java_call_counter() { _java_call_counter++; }
925 void dec_java_call_counter() {
926 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
927 _java_call_counter--;
928 }
929 private: // restore original namespace restriction
930 #endif // ifdef ASSERT
931
932 #ifndef PRODUCT
933 public:
934 enum {
935 jump_ring_buffer_size = 16
936 };
937 private: // restore original namespace restriction
938 #endif
939
940 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
941
942 ThreadFunction _entry_point;
943
944 JNIEnv _jni_environment;
945
946 // Deopt support
947 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
948
949 intptr_t* _must_deopt_id; // id of frame that needs to be deopted once we
950 // transition out of native
951 CompiledMethod* _deopt_nmethod; // CompiledMethod that is currently being deoptimized
952 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
953 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
954 // Because deoptimization is lazy we must save jvmti requests to set locals
955 // in compiled frames until we deoptimize and we have an interpreter frame.
956 // This holds the pointer to array (yeah like there might be more than one) of
957 // description of compiled vframes that have locals that need to be updated.
958 GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
959
960 // Handshake value for fixing 6243940. We need a place for the i2c
961 // adapter to store the callee Method*. This value is NEVER live
962 // across a gc point so it does NOT have to be gc'd
963 // The handshake is open ended since we can't be certain that it will
964 // be NULLed. This is because we rarely ever see the race and end up
965 // in handle_wrong_method which is the backend of the handshake. See
966 // code in i2c adapters and handle_wrong_method.
967
968 Method* _callee_target;
969
970 // Used to pass back results to the interpreter or generated code running Java code.
971 oop _vm_result; // oop result is GC-preserved
972 Metadata* _vm_result_2; // non-oop result
973 oop _return_buffered_value; // buffered value being returned
974
975 // See ReduceInitialCardMarks: this holds the precise space interval of
976 // the most recent slow path allocation for which compiled code has
977 // elided card-marks for performance along the fast-path.
978 MemRegion _deferred_card_mark;
979
980 MonitorChunk* _monitor_chunks; // Contains the off stack monitors
981 // allocated during deoptimization
982 // and by JNI_MonitorEnter/Exit
983
984 // Async. requests support
985 enum AsyncRequests {
986 _no_async_condition = 0,
987 _async_exception,
988 _async_unsafe_access_error
989 };
990 AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
991 oop _pending_async_exception;
992
993 // Safepoint support
994 public: // Expose _thread_state for SafeFetchInt()
995 volatile JavaThreadState _thread_state;
996 private:
997 ThreadSafepointState *_safepoint_state; // Holds information about a thread during a safepoint
998 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
999
1000 // JavaThread termination support
1001 enum TerminatedTypes {
1002 _not_terminated = 0xDEAD - 2,
1003 _thread_exiting, // JavaThread::exit() has been called for this thread
1004 _thread_terminated, // JavaThread is removed from thread list
1005 _vm_exited // JavaThread is still executing native code, but VM is terminated
1006 // only VM_Exit can set _vm_exited
1007 };
1008
1009 // In general a JavaThread's _terminated field transitions as follows:
1010 //
1011 // _not_terminated => _thread_exiting => _thread_terminated
1012 //
1013 // _vm_exited is a special value to cover the case of a JavaThread
1014 // executing native code after the VM itself is terminated.
1015 volatile TerminatedTypes _terminated;
1016 // suspend/resume support
1017 volatile bool _suspend_equivalent; // Suspend equivalent condition
1018 jint _in_deopt_handler; // count of deoptimization
1019 // handlers thread is in
1020 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
1021 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
1022 // never locked) when throwing an exception. Used by interpreter only.
1023
1024 // JNI attach states:
1025 enum JNIAttachStates {
1026 _not_attaching_via_jni = 1, // thread is not attaching via JNI
1027 _attaching_via_jni, // thread is attaching via JNI
1028 _attached_via_jni // thread has attached via JNI
1029 };
1030
1031 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
1032 // A native thread that is attaching via JNI starts with a value
1033 // of _attaching_via_jni and transitions to _attached_via_jni.
1034 volatile JNIAttachStates _jni_attach_state;
1035
1036 public:
1037 // State of the stack guard pages for this thread.
1038 enum StackGuardState {
1039 stack_guard_unused, // not needed
1040 stack_guard_reserved_disabled,
1041 stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
1042 stack_guard_enabled // enabled
1043 };
1044
1045 private:
1046
1047 #if INCLUDE_JVMCI
1048 // The _pending_* fields below are used to communicate extra information
1049 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
1050
1051 // Communicates the DeoptReason and DeoptAction of the uncommon trap
1052 int _pending_deoptimization;
1053
1054 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
1055 // before the monitor has been acquired.
1056 bool _pending_monitorenter;
1057
1058 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
1059 bool _pending_transfer_to_interpreter;
1060
1061 // Guard for re-entrant call to JVMCIRuntime::adjust_comp_level
1062 bool _adjusting_comp_level;
1063
1064 // An id of a speculation that JVMCI compiled code can use to further describe and
1065 // uniquely identify the speculative optimization guarded by the uncommon trap
1066 long _pending_failed_speculation;
1067
1068 // These fields are mutually exclusive in terms of live ranges.
1069 union {
1070 // Communicates the pc at which the most recent implicit exception occurred
1071 // from the signal handler to a deoptimization stub.
1072 address _implicit_exception_pc;
1073
1074 // Communicates an alternative call target to an i2c stub from a JavaCall .
1075 address _alternate_call_target;
1076 } _jvmci;
1077
1078 // Support for high precision, thread sensitive counters in JVMCI compiled code.
1079 jlong* _jvmci_counters;
1080
1081 public:
1082 static jlong* _jvmci_old_thread_counters;
1083 static void collect_counters(typeArrayOop array);
1084 private:
1085 #endif // INCLUDE_JVMCI
1086
1087 StackGuardState _stack_guard_state;
1088
1089 // Precompute the limit of the stack as used in stack overflow checks.
1090 // We load it from here to simplify the stack overflow check in assembly.
1091 address _stack_overflow_limit;
1092 address _reserved_stack_activation;
1093
1094 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1095 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1096 // code)
1097 volatile oop _exception_oop; // Exception thrown in compiled code
1098 volatile address _exception_pc; // PC where exception happened
1099 volatile address _exception_handler_pc; // PC for handler of exception
1100 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
1101
1102 private:
1103 // support for JNI critical regions
1104 jint _jni_active_critical; // count of entries into JNI critical region
1105
1106 // Checked JNI: function name requires exception check
1107 char* _pending_jni_exception_check_fn;
1108
1109 // For deadlock detection.
1110 int _depth_first_number;
1111
1112 // JVMTI PopFrame support
1113 // This is set to popframe_pending to signal that top Java frame should be popped immediately
1114 int _popframe_condition;
1115
1116 // If reallocation of scalar replaced objects fails, we throw OOM
1117 // and during exception propagation, pop the top
1118 // _frames_to_pop_failed_realloc frames, the ones that reference
1119 // failed reallocations.
1120 int _frames_to_pop_failed_realloc;
1121
1122 #ifndef PRODUCT
1123 int _jmp_ring_index;
1124 struct {
1125 // We use intptr_t instead of address so debugger doesn't try and display strings
1126 intptr_t _target;
1127 intptr_t _instruction;
1128 const char* _file;
1129 int _line;
1130 } _jmp_ring[jump_ring_buffer_size];
1131 #endif // PRODUCT
1132
1133 friend class VMThread;
1134 friend class ThreadWaitTransition;
1135 friend class VM_Exit;
1136
1137 void initialize(); // Initialized the instance variables
1138
1139 public:
1140 // Constructor
1141 JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1142 JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1143 ~JavaThread();
1144
1145 #ifdef ASSERT
1146 // verify this JavaThread hasn't be published in the Threads::list yet
1147 void verify_not_published();
1148 #endif
1149
1150 //JNI functiontable getter/setter for JVMTI jni function table interception API.
1151 void set_jni_functions(struct JNINativeInterface_* functionTable) {
1152 _jni_environment.functions = functionTable;
1153 }
1154 struct JNINativeInterface_* get_jni_functions() {
1155 return (struct JNINativeInterface_ *)_jni_environment.functions;
1156 }
1157
1158 // This function is called at thread creation to allow
1159 // platform specific thread variables to be initialized.
1160 void cache_global_variables();
1161
1162 // Executes Shutdown.shutdown()
1163 void invoke_shutdown_hooks();
1164
1165 // Cleanup on thread exit
1166 enum ExitType {
1167 normal_exit,
1168 jni_detach
1169 };
1170 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1171
1172 void cleanup_failed_attach_current_thread();
1173
1174 // Testers
1175 virtual bool is_Java_thread() const { return true; }
1176 virtual bool can_call_java() const { return true; }
1177
1178 // Thread chain operations
1179 JavaThread* next() const { return _next; }
1180 void set_next(JavaThread* p) { _next = p; }
1181
1182 // Thread oop. threadObj() can be NULL for initial JavaThread
1183 // (or for threads attached via JNI)
1184 oop threadObj() const { return _threadObj; }
1185 void set_threadObj(oop p) { _threadObj = p; }
1186
1187 ThreadPriority java_priority() const; // Read from threadObj()
1188
1189 // Prepare thread and add to priority queue. If a priority is
1190 // not specified, use the priority of the thread object. Threads_lock
1191 // must be held while this function is called.
1192 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1193
1194 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
1195 address saved_exception_pc() { return _saved_exception_pc; }
1196
1197
1198 ThreadFunction entry_point() const { return _entry_point; }
1199
1200 // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1201 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1202
1203 // Last frame anchor routines
1204
1205 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
1206
1207 // last_Java_sp
1208 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
1209 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
1210
1211 // last_Java_pc
1212
1213 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
1214
1215 // Safepoint support
1216 #if !(defined(PPC64) || defined(AARCH64))
1217 JavaThreadState thread_state() const { return _thread_state; }
1218 void set_thread_state(JavaThreadState s) { _thread_state = s; }
1219 #else
1220 // Use membars when accessing volatile _thread_state. See
1221 // Threads::create_vm() for size checks.
1222 inline JavaThreadState thread_state() const;
1223 inline void set_thread_state(JavaThreadState s);
1224 #endif
1225 ThreadSafepointState *safepoint_state() const { return _safepoint_state; }
1226 void set_safepoint_state(ThreadSafepointState *state) { _safepoint_state = state; }
1227 bool is_at_poll_safepoint() { return _safepoint_state->is_at_poll_safepoint(); }
1228
1229 // JavaThread termination and lifecycle support:
1230 void smr_delete();
1231 bool on_thread_list() const { return _on_thread_list; }
1232 void set_on_thread_list() { _on_thread_list = true; }
1233
1234 // thread has called JavaThread::exit() or is terminated
1235 bool is_exiting() const;
1236 // thread is terminated (no longer on the threads list); we compare
1237 // against the two non-terminated values so that a freed JavaThread
1238 // will also be considered terminated.
1239 bool check_is_terminated(TerminatedTypes l_terminated) const {
1240 return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1241 }
1242 bool is_terminated() const;
1243 void set_terminated(TerminatedTypes t);
1244 // special for Threads::remove() which is static:
1245 void set_terminated_value();
1246 void block_if_vm_exited();
1247
1248 bool doing_unsafe_access() { return _doing_unsafe_access; }
1249 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
1250
1251 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
1252 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1253
1254 inline void set_polling_page_release(void* poll_value);
1255 inline void set_polling_page(void* poll_value);
1256 inline volatile void* get_polling_page();
1257
1258 private:
1259 // Support for thread handshake operations
1260 HandshakeState _handshake;
1261 public:
1262 void set_handshake_operation(HandshakeOperation* op) {
1263 _handshake.set_operation(this, op);
1264 }
1265
1266 bool has_handshake() const {
1267 return _handshake.has_operation();
1268 }
1269
1270 void cancel_handshake() {
1271 _handshake.cancel(this);
1272 }
1273
1274 void handshake_process_by_self() {
1275 _handshake.process_by_self(this);
1276 }
1277
1278 void handshake_process_by_vmthread() {
1279 _handshake.process_by_vmthread(this);
1280 }
1281
1282 // Suspend/resume support for JavaThread
1283 private:
1284 inline void set_ext_suspended();
1285 inline void clear_ext_suspended();
1286
1287 public:
1288 void java_suspend();
1289 void java_resume();
1290 int java_suspend_self();
1291
1292 void check_and_wait_while_suspended() {
1293 assert(JavaThread::current() == this, "sanity check");
1294
1295 bool do_self_suspend;
1296 do {
1297 // were we externally suspended while we were waiting?
1298 do_self_suspend = handle_special_suspend_equivalent_condition();
1299 if (do_self_suspend) {
1300 // don't surprise the thread that suspended us by returning
1301 java_suspend_self();
1302 set_suspend_equivalent();
1303 }
1304 } while (do_self_suspend);
1305 }
1306 static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1307 // Check for async exception in addition to safepoint and suspend request.
1308 static void check_special_condition_for_native_trans(JavaThread *thread);
1309
1310 // Same as check_special_condition_for_native_trans but finishes the
1311 // transition into thread_in_Java mode so that it can potentially
1312 // block.
1313 static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1314
1315 bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1316 bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1317 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1318 // Warning: is_ext_suspend_completed() may temporarily drop the
1319 // SR_lock to allow the thread to reach a stable thread state if
1320 // it is currently in a transient thread state.
1321 return is_ext_suspend_completed(false /* !called_by_wait */,
1322 SuspendRetryDelay, bits);
1323 }
1324
1325 // We cannot allow wait_for_ext_suspend_completion() to run forever or
1326 // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1327 // passed as the count and delay parameters. Experiments with specific
1328 // calls to wait_for_ext_suspend_completion() can be done by passing
1329 // other values in the code. Experiments with all calls can be done
1330 // via the appropriate -XX options.
1331 bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1332
1333 // test for suspend - most (all?) of these should go away
1334 bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits);
1335
1336 inline void set_external_suspend();
1337 inline void clear_external_suspend();
1338
1339 inline void set_deopt_suspend();
1340 inline void clear_deopt_suspend();
1341 bool is_deopt_suspend() { return (_suspend_flags & _deopt_suspend) != 0; }
1342
1343 bool is_external_suspend() const {
1344 return (_suspend_flags & _external_suspend) != 0;
1345 }
1346 // Whenever a thread transitions from native to vm/java it must suspend
1347 // if external|deopt suspend is present.
1348 bool is_suspend_after_native() const {
1349 return (_suspend_flags & (_external_suspend | _deopt_suspend)) != 0;
1350 }
1351
1352 // external suspend request is completed
1353 bool is_ext_suspended() const {
1354 return (_suspend_flags & _ext_suspended) != 0;
1355 }
1356
1357 bool is_external_suspend_with_lock() const {
1358 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1359 return is_external_suspend();
1360 }
1361
1362 // Special method to handle a pending external suspend request
1363 // when a suspend equivalent condition lifts.
1364 bool handle_special_suspend_equivalent_condition() {
1365 assert(is_suspend_equivalent(),
1366 "should only be called in a suspend equivalence condition");
1367 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1368 bool ret = is_external_suspend();
1369 if (!ret) {
1370 // not about to self-suspend so clear suspend equivalence
1371 clear_suspend_equivalent();
1372 }
1373 // implied else:
1374 // We have a pending external suspend request so we leave the
1375 // suspend_equivalent flag set until java_suspend_self() sets
1376 // the ext_suspended flag and clears the suspend_equivalent
1377 // flag. This insures that wait_for_ext_suspend_completion()
1378 // will return consistent values.
1379 return ret;
1380 }
1381
1382 // utility methods to see if we are doing some kind of suspension
1383 bool is_being_ext_suspended() const {
1384 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1385 return is_ext_suspended() || is_external_suspend();
1386 }
1387
1388 bool is_suspend_equivalent() const { return _suspend_equivalent; }
1389
1390 void set_suspend_equivalent() { _suspend_equivalent = true; }
1391 void clear_suspend_equivalent() { _suspend_equivalent = false; }
1392
1393 // Thread.stop support
1394 void send_thread_stop(oop throwable);
1395 AsyncRequests clear_special_runtime_exit_condition() {
1396 AsyncRequests x = _special_runtime_exit_condition;
1397 _special_runtime_exit_condition = _no_async_condition;
1398 return x;
1399 }
1400
1401 // Are any async conditions present?
1402 bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1403
1404 void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1405
1406 // these next two are also used for self-suspension and async exception support
1407 void handle_special_runtime_exit_condition(bool check_asyncs = true);
1408
1409 // Return true if JavaThread has an asynchronous condition or
1410 // if external suspension is requested.
1411 bool has_special_runtime_exit_condition() {
1412 // Because we don't use is_external_suspend_with_lock
1413 // it is possible that we won't see an asynchronous external suspend
1414 // request that has just gotten started, i.e., SR_lock grabbed but
1415 // _external_suspend field change either not made yet or not visible
1416 // yet. However, this is okay because the request is asynchronous and
1417 // we will see the new flag value the next time through. It's also
1418 // possible that the external suspend request is dropped after
1419 // we have checked is_external_suspend(), we will recheck its value
1420 // under SR_lock in java_suspend_self().
1421 return (_special_runtime_exit_condition != _no_async_condition) ||
1422 is_external_suspend() || is_trace_suspend();
1423 }
1424
1425 void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; }
1426
1427 inline void set_pending_async_exception(oop e);
1428
1429 // Fast-locking support
1430 bool is_lock_owned(address adr) const;
1431
1432 // Accessors for vframe array top
1433 // The linked list of vframe arrays are sorted on sp. This means when we
1434 // unpack the head must contain the vframe array to unpack.
1435 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1436 vframeArray* vframe_array_head() const { return _vframe_array_head; }
1437
1438 // Side structure for deferring update of java frame locals until deopt occurs
1439 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1440 void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1441
1442 // These only really exist to make debugging deopt problems simpler
1443
1444 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1445 vframeArray* vframe_array_last() const { return _vframe_array_last; }
1446
1447 // The special resourceMark used during deoptimization
1448
1449 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
1450 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
1451
1452 intptr_t* must_deopt_id() { return _must_deopt_id; }
1453 void set_must_deopt_id(intptr_t* id) { _must_deopt_id = id; }
1454 void clear_must_deopt_id() { _must_deopt_id = NULL; }
1455
1456 void set_deopt_compiled_method(CompiledMethod* nm) { _deopt_nmethod = nm; }
1457 CompiledMethod* deopt_compiled_method() { return _deopt_nmethod; }
1458
1459 Method* callee_target() const { return _callee_target; }
1460 void set_callee_target (Method* x) { _callee_target = x; }
1461
1462 // Oop results of vm runtime calls
1463 oop vm_result() const { return _vm_result; }
1464 void set_vm_result (oop x) { _vm_result = x; }
1465
1466 Metadata* vm_result_2() const { return _vm_result_2; }
1467 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
1468
1469 oop return_buffered_value() const { return _return_buffered_value; }
1470 void set_return_buffered_value(oop val) { _return_buffered_value = val; }
1471
1472 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
1473 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
1474
1475 #if INCLUDE_JVMCI
1476 int pending_deoptimization() const { return _pending_deoptimization; }
1477 long pending_failed_speculation() const { return _pending_failed_speculation; }
1478 bool adjusting_comp_level() const { return _adjusting_comp_level; }
1479 void set_adjusting_comp_level(bool b) { _adjusting_comp_level = b; }
1480 bool has_pending_monitorenter() const { return _pending_monitorenter; }
1481 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
1482 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
1483 void set_pending_failed_speculation(long failed_speculation) { _pending_failed_speculation = failed_speculation; }
1484 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1485 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1486 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1487 #endif // INCLUDE_JVMCI
1488
1489 // Exception handling for compiled methods
1490 oop exception_oop() const { return _exception_oop; }
1491 address exception_pc() const { return _exception_pc; }
1492 address exception_handler_pc() const { return _exception_handler_pc; }
1493 bool is_method_handle_return() const { return _is_method_handle_return == 1; }
1494
1495 void set_exception_oop(oop o) { (void)const_cast<oop&>(_exception_oop = o); }
1496 void set_exception_pc(address a) { _exception_pc = a; }
1497 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
1498 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
1499
1500 void clear_exception_oop_and_pc() {
1501 set_exception_oop(NULL);
1502 set_exception_pc(NULL);
1503 }
1504
1505 // Stack overflow support
1506 //
1507 // (small addresses)
1508 //
1509 // -- <-- stack_end() ---
1510 // | |
1511 // | red pages |
1512 // | |
1513 // -- <-- stack_red_zone_base() |
1514 // | |
1515 // | guard
1516 // | yellow pages zone
1517 // | |
1518 // | |
1519 // -- <-- stack_yellow_zone_base() |
1520 // | |
1521 // | |
1522 // | reserved pages |
1523 // | |
1524 // -- <-- stack_reserved_zone_base() --- ---
1525 // /|\ shadow <-- stack_overflow_limit() (somewhere in here)
1526 // | zone
1527 // \|/ size
1528 // some untouched memory ---
1529 //
1530 //
1531 // --
1532 // |
1533 // | shadow zone
1534 // |
1535 // --
1536 // x frame n
1537 // --
1538 // x frame n-1
1539 // x
1540 // --
1541 // ...
1542 //
1543 // --
1544 // x frame 0
1545 // -- <-- stack_base()
1546 //
1547 // (large addresses)
1548 //
1549
1550 private:
1551 // These values are derived from flags StackRedPages, StackYellowPages,
1552 // StackReservedPages and StackShadowPages. The zone size is determined
1553 // ergonomically if page_size > 4K.
1554 static size_t _stack_red_zone_size;
1555 static size_t _stack_yellow_zone_size;
1556 static size_t _stack_reserved_zone_size;
1557 static size_t _stack_shadow_zone_size;
1558 public:
1559 inline size_t stack_available(address cur_sp);
1560
1561 static size_t stack_red_zone_size() {
1562 assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1563 return _stack_red_zone_size;
1564 }
1565 static void set_stack_red_zone_size(size_t s) {
1566 assert(is_aligned(s, os::vm_page_size()),
1567 "We can not protect if the red zone size is not page aligned.");
1568 assert(_stack_red_zone_size == 0, "This should be called only once.");
1569 _stack_red_zone_size = s;
1570 }
1571 address stack_red_zone_base() {
1572 return (address)(stack_end() + stack_red_zone_size());
1573 }
1574 bool in_stack_red_zone(address a) {
1575 return a <= stack_red_zone_base() && a >= stack_end();
1576 }
1577
1578 static size_t stack_yellow_zone_size() {
1579 assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1580 return _stack_yellow_zone_size;
1581 }
1582 static void set_stack_yellow_zone_size(size_t s) {
1583 assert(is_aligned(s, os::vm_page_size()),
1584 "We can not protect if the yellow zone size is not page aligned.");
1585 assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1586 _stack_yellow_zone_size = s;
1587 }
1588
1589 static size_t stack_reserved_zone_size() {
1590 // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1591 return _stack_reserved_zone_size;
1592 }
1593 static void set_stack_reserved_zone_size(size_t s) {
1594 assert(is_aligned(s, os::vm_page_size()),
1595 "We can not protect if the reserved zone size is not page aligned.");
1596 assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1597 _stack_reserved_zone_size = s;
1598 }
1599 address stack_reserved_zone_base() {
1600 return (address)(stack_end() +
1601 (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1602 }
1603 bool in_stack_reserved_zone(address a) {
1604 return (a <= stack_reserved_zone_base()) &&
1605 (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1606 }
1607
1608 static size_t stack_yellow_reserved_zone_size() {
1609 return _stack_yellow_zone_size + _stack_reserved_zone_size;
1610 }
1611 bool in_stack_yellow_reserved_zone(address a) {
1612 return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1613 }
1614
1615 // Size of red + yellow + reserved zones.
1616 static size_t stack_guard_zone_size() {
1617 return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1618 }
1619
1620 static size_t stack_shadow_zone_size() {
1621 assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1622 return _stack_shadow_zone_size;
1623 }
1624 static void set_stack_shadow_zone_size(size_t s) {
1625 // The shadow area is not allocated or protected, so
1626 // it needs not be page aligned.
1627 // But the stack bang currently assumes that it is a
1628 // multiple of page size. This guarantees that the bang
1629 // loop touches all pages in the shadow zone.
1630 // This can be guaranteed differently, as well. E.g., if
1631 // the page size is a multiple of 4K, banging in 4K steps
1632 // suffices to touch all pages. (Some pages are banged
1633 // several times, though.)
1634 assert(is_aligned(s, os::vm_page_size()),
1635 "Stack bang assumes multiple of page size.");
1636 assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1637 _stack_shadow_zone_size = s;
1638 }
1639
1640 void create_stack_guard_pages();
1641 void remove_stack_guard_pages();
1642
1643 void enable_stack_reserved_zone();
1644 void disable_stack_reserved_zone();
1645 void enable_stack_yellow_reserved_zone();
1646 void disable_stack_yellow_reserved_zone();
1647 void enable_stack_red_zone();
1648 void disable_stack_red_zone();
1649
1650 inline bool stack_guard_zone_unused();
1651 inline bool stack_yellow_reserved_zone_disabled();
1652 inline bool stack_reserved_zone_disabled();
1653 inline bool stack_guards_enabled();
1654
1655 address reserved_stack_activation() const { return _reserved_stack_activation; }
1656 void set_reserved_stack_activation(address addr) {
1657 assert(_reserved_stack_activation == stack_base()
1658 || _reserved_stack_activation == NULL
1659 || addr == stack_base(), "Must not be set twice");
1660 _reserved_stack_activation = addr;
1661 }
1662
1663 // Attempt to reguard the stack after a stack overflow may have occurred.
1664 // Returns true if (a) guard pages are not needed on this thread, (b) the
1665 // pages are already guarded, or (c) the pages were successfully reguarded.
1666 // Returns false if there is not enough stack space to reguard the pages, in
1667 // which case the caller should unwind a frame and try again. The argument
1668 // should be the caller's (approximate) sp.
1669 bool reguard_stack(address cur_sp);
1670 // Similar to above but see if current stackpoint is out of the guard area
1671 // and reguard if possible.
1672 bool reguard_stack(void);
1673
1674 address stack_overflow_limit() { return _stack_overflow_limit; }
1675 void set_stack_overflow_limit() {
1676 _stack_overflow_limit =
1677 stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1678 }
1679
1680 // Misc. accessors/mutators
1681 void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; }
1682 void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; }
1683 bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; }
1684
1685 #ifndef PRODUCT
1686 void record_jump(address target, address instr, const char* file, int line);
1687 #endif // PRODUCT
1688
1689 // For assembly stub generation
1690 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
1691 #ifndef PRODUCT
1692 static ByteSize jmp_ring_index_offset() { return byte_offset_of(JavaThread, _jmp_ring_index); }
1693 static ByteSize jmp_ring_offset() { return byte_offset_of(JavaThread, _jmp_ring); }
1694 #endif // PRODUCT
1695 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
1696 static ByteSize pending_jni_exception_check_fn_offset() {
1697 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1698 }
1699 static ByteSize last_Java_sp_offset() {
1700 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1701 }
1702 static ByteSize last_Java_pc_offset() {
1703 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1704 }
1705 static ByteSize frame_anchor_offset() {
1706 return byte_offset_of(JavaThread, _anchor);
1707 }
1708 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
1709 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); }
1710 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); }
1711 static ByteSize return_buffered_value_offset() { return byte_offset_of(JavaThread, _return_buffered_value); }
1712 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
1713 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
1714 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
1715 #if INCLUDE_JVMCI
1716 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1717 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
1718 static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1719 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1720 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1721 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
1722 #endif // INCLUDE_JVMCI
1723 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
1724 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
1725 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
1726 static ByteSize stack_overflow_limit_offset() { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1727 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1728 static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state); }
1729 static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1730 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
1731
1732 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1733 static ByteSize should_post_on_exceptions_flag_offset() {
1734 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1735 }
1736
1737 // Returns the jni environment for this thread
1738 JNIEnv* jni_environment() { return &_jni_environment; }
1739
1740 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1741 JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1742 // Only return NULL if thread is off the thread list; starting to
1743 // exit should not return NULL.
1744 if (thread_from_jni_env->is_terminated()) {
1745 thread_from_jni_env->block_if_vm_exited();
1746 return NULL;
1747 } else {
1748 return thread_from_jni_env;
1749 }
1750 }
1751
1752 // JNI critical regions. These can nest.
1753 bool in_critical() { return _jni_active_critical > 0; }
1754 bool in_last_critical() { return _jni_active_critical == 1; }
1755 void enter_critical() {
1756 assert(Thread::current() == this ||
1757 (Thread::current()->is_VM_thread() &&
1758 SafepointSynchronize::is_synchronizing()),
1759 "this must be current thread or synchronizing");
1760 _jni_active_critical++;
1761 }
1762 void exit_critical() {
1763 assert(Thread::current() == this, "this must be current thread");
1764 _jni_active_critical--;
1765 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1766 }
1767
1768 // Checked JNI: is the programmer required to check for exceptions, if so specify
1769 // which function name. Returning to a Java frame should implicitly clear the
1770 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1771 // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1772 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1773 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1774 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1775 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1776 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1777
1778 // For deadlock detection
1779 int depth_first_number() { return _depth_first_number; }
1780 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1781
1782 private:
1783 void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1784
1785 public:
1786 MonitorChunk* monitor_chunks() const { return _monitor_chunks; }
1787 void add_monitor_chunk(MonitorChunk* chunk);
1788 void remove_monitor_chunk(MonitorChunk* chunk);
1789 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
1790 void inc_in_deopt_handler() { _in_deopt_handler++; }
1791 void dec_in_deopt_handler() {
1792 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1793 if (_in_deopt_handler > 0) { // robustness
1794 _in_deopt_handler--;
1795 }
1796 }
1797
1798 private:
1799 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1800
1801 public:
1802
1803 // Frame iteration; calls the function f for all frames on the stack
1804 void frames_do(void f(frame*, const RegisterMap*));
1805
1806 // Memory operations
1807 void oops_do(OopClosure* f, CodeBlobClosure* cf);
1808
1809 // Sweeper operations
1810 virtual void nmethods_do(CodeBlobClosure* cf);
1811
1812 // RedefineClasses Support
1813 void metadata_do(void f(Metadata*));
1814
1815 // Misc. operations
1816 char* name() const { return (char*)get_thread_name(); }
1817 void print_on(outputStream* st, bool print_extended_info) const;
1818 void print_on(outputStream* st) const { print_on(st, false); }
1819 void print_value();
1820 void print_thread_state_on(outputStream*) const PRODUCT_RETURN;
1821 void print_thread_state() const PRODUCT_RETURN;
1822 void print_on_error(outputStream* st, char* buf, int buflen) const;
1823 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1824 void verify();
1825 const char* get_thread_name() const;
1826 private:
1827 // factor out low-level mechanics for use in both normal and error cases
1828 const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1829 public:
1830 const char* get_threadgroup_name() const;
1831 const char* get_parent_name() const;
1832
1833 // Accessing frames
1834 frame last_frame() {
1835 _anchor.make_walkable(this);
1836 return pd_last_frame();
1837 }
1838 javaVFrame* last_java_vframe(RegisterMap* reg_map);
1839
1840 // Returns method at 'depth' java or native frames down the stack
1841 // Used for security checks
1842 Klass* security_get_caller_class(int depth);
1843
1844 // Print stack trace in external format
1845 void print_stack_on(outputStream* st);
1846 void print_stack() { print_stack_on(tty); }
1847
1848 // Print stack traces in various internal formats
1849 void trace_stack() PRODUCT_RETURN;
1850 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1851 void trace_frames() PRODUCT_RETURN;
1852 void trace_oops() PRODUCT_RETURN;
1853
1854 // Print an annotated view of the stack frames
1855 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1856 void validate_frame_layout() {
1857 print_frame_layout(0, true);
1858 }
1859
1860 // Returns the number of stack frames on the stack
1861 int depth() const;
1862
1863 // Function for testing deoptimization
1864 void deoptimize();
1865 void make_zombies();
1866
1867 void deoptimized_wrt_marked_nmethods();
1868
1869 public:
1870 // Returns the running thread as a JavaThread
1871 static inline JavaThread* current();
1872
1873 // Returns the active Java thread. Do not use this if you know you are calling
1874 // from a JavaThread, as it's slower than JavaThread::current. If called from
1875 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1876 // operation. You may not want that either.
1877 static JavaThread* active();
1878
1879 inline CompilerThread* as_CompilerThread();
1880
1881 public:
1882 virtual void run();
1883 void thread_main_inner();
1884
1885 private:
1886 // PRIVILEGED STACK
1887 PrivilegedElement* _privileged_stack_top;
1888 GrowableArray<oop>* _array_for_gc;
1889 public:
1890
1891 // Returns the privileged_stack information.
1892 PrivilegedElement* privileged_stack_top() const { return _privileged_stack_top; }
1893 void set_privileged_stack_top(PrivilegedElement *e) { _privileged_stack_top = e; }
1894 void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1895
1896 public:
1897 // Thread local information maintained by JVMTI.
1898 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1899 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1900 // getter is used to get this JavaThread's JvmtiThreadState if it has
1901 // one which means NULL can be returned. JvmtiThreadState::state_for()
1902 // is used to get the specified JavaThread's JvmtiThreadState if it has
1903 // one or it allocates a new JvmtiThreadState for the JavaThread and
1904 // returns it. JvmtiThreadState::state_for() will return NULL only if
1905 // the specified JavaThread is exiting.
1906 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1907 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1908
1909 // JVMTI PopFrame support
1910 // Setting and clearing popframe_condition
1911 // All of these enumerated values are bits. popframe_pending
1912 // indicates that a PopFrame() has been requested and not yet been
1913 // completed. popframe_processing indicates that that PopFrame() is in
1914 // the process of being completed. popframe_force_deopt_reexecution_bit
1915 // indicates that special handling is required when returning to a
1916 // deoptimized caller.
1917 enum PopCondition {
1918 popframe_inactive = 0x00,
1919 popframe_pending_bit = 0x01,
1920 popframe_processing_bit = 0x02,
1921 popframe_force_deopt_reexecution_bit = 0x04
1922 };
1923 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1924 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1925 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1926 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1927 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1928 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1929 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1930 void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1931 #ifdef CC_INTERP
1932 bool pop_frame_pending(void) { return ((_popframe_condition & popframe_pending_bit) != 0); }
1933 void clr_pop_frame_pending(void) { _popframe_condition = popframe_inactive; }
1934 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1935 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
1936 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
1937 #endif
1938
1939 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
1940 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
1941 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
1942
1943 private:
1944 // Saved incoming arguments to popped frame.
1945 // Used only when popped interpreted frame returns to deoptimized frame.
1946 void* _popframe_preserved_args;
1947 int _popframe_preserved_args_size;
1948
1949 public:
1950 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
1951 void* popframe_preserved_args();
1952 ByteSize popframe_preserved_args_size();
1953 WordSize popframe_preserved_args_size_in_words();
1954 void popframe_free_preserved_args();
1955
1956
1957 private:
1958 JvmtiThreadState *_jvmti_thread_state;
1959
1960 // Used by the interpreter in fullspeed mode for frame pop, method
1961 // entry, method exit and single stepping support. This field is
1962 // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
1963 // It can be set to zero asynchronously (i.e., without a VM operation
1964 // or a lock) so we have to be very careful.
1965 int _interp_only_mode;
1966
1967 public:
1968 // used by the interpreter for fullspeed debugging support (see above)
1969 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1970 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
1971 int get_interp_only_mode() { return _interp_only_mode; }
1972 void increment_interp_only_mode() { ++_interp_only_mode; }
1973 void decrement_interp_only_mode() { --_interp_only_mode; }
1974
1975 // support for cached flag that indicates whether exceptions need to be posted for this thread
1976 // if this is false, we can avoid deoptimizing when events are thrown
1977 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1978 private:
1979 int _should_post_on_exceptions_flag;
1980
1981 public:
1982 int should_post_on_exceptions_flag() { return _should_post_on_exceptions_flag; }
1983 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
1984
1985 private:
1986 ThreadStatistics *_thread_stat;
1987
1988 public:
1989 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
1990
1991 // Return a blocker object for which this thread is blocked parking.
1992 oop current_park_blocker();
1993
1994 private:
1995 static size_t _stack_size_at_create;
1996
1997 public:
1998 static inline size_t stack_size_at_create(void) {
1999 return _stack_size_at_create;
2000 }
2001 static inline void set_stack_size_at_create(size_t value) {
2002 _stack_size_at_create = value;
2003 }
2004
2005 // Machine dependent stuff
2006 #include OS_CPU_HEADER(thread)
2007
2008 public:
2009 void set_blocked_on_compilation(bool value) {
2010 _blocked_on_compilation = value;
2011 }
2012
2013 bool blocked_on_compilation() {
2014 return _blocked_on_compilation;
2015 }
2016 protected:
2017 bool _blocked_on_compilation;
2018
2019
2020 // JSR166 per-thread parker
2021 private:
2022 Parker* _parker;
2023 public:
2024 Parker* parker() { return _parker; }
2025
2026 // Biased locking support
2027 private:
2028 GrowableArray<MonitorInfo*>* _cached_monitor_info;
2029 public:
2030 GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
2031 void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
2032
2033 // clearing/querying jni attach status
2034 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
2035 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
2036 inline void set_done_attaching_via_jni();
2037 };
2038
2039 // Inline implementation of JavaThread::current
2040 inline JavaThread* JavaThread::current() {
2041 Thread* thread = Thread::current();
2042 assert(thread->is_Java_thread(), "just checking");
2043 return (JavaThread*)thread;
2044 }
2045
2046 inline CompilerThread* JavaThread::as_CompilerThread() {
2047 assert(is_Compiler_thread(), "just checking");
2048 return (CompilerThread*)this;
2049 }
2050
2051 // Dedicated thread to sweep the code cache
2052 class CodeCacheSweeperThread : public JavaThread {
2053 CompiledMethod* _scanned_compiled_method; // nmethod being scanned by the sweeper
2054 public:
2055 CodeCacheSweeperThread();
2056 // Track the nmethod currently being scanned by the sweeper
2057 void set_scanned_compiled_method(CompiledMethod* cm) {
2058 assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value");
2059 _scanned_compiled_method = cm;
2060 }
2061
2062 // Hide sweeper thread from external view.
2063 bool is_hidden_from_external_view() const { return true; }
2064
2065 bool is_Code_cache_sweeper_thread() const { return true; }
2066
2067 // Prevent GC from unloading _scanned_compiled_method
2068 void oops_do(OopClosure* f, CodeBlobClosure* cf);
2069 void nmethods_do(CodeBlobClosure* cf);
2070 };
2071
2072 // A thread used for Compilation.
2073 class CompilerThread : public JavaThread {
2074 friend class VMStructs;
2075 private:
2076 CompilerCounters* _counters;
2077
2078 ciEnv* _env;
2079 CompileLog* _log;
2080 CompileTask* volatile _task; // print_threads_compiling can read this concurrently.
2081 CompileQueue* _queue;
2082 BufferBlob* _buffer_blob;
2083
2084 AbstractCompiler* _compiler;
2085 TimeStamp _idle_time;
2086
2087 public:
2088
2089 static CompilerThread* current();
2090
2091 CompilerThread(CompileQueue* queue, CompilerCounters* counters);
2092 ~CompilerThread();
2093
2094 bool is_Compiler_thread() const { return true; }
2095
2096 virtual bool can_call_java() const;
2097
2098 // Hide native compiler threads from external view.
2099 bool is_hidden_from_external_view() const { return !can_call_java(); }
2100
2101 void set_compiler(AbstractCompiler* c) { _compiler = c; }
2102 AbstractCompiler* compiler() const { return _compiler; }
2103
2104 CompileQueue* queue() const { return _queue; }
2105 CompilerCounters* counters() const { return _counters; }
2106
2107 // Get/set the thread's compilation environment.
2108 ciEnv* env() { return _env; }
2109 void set_env(ciEnv* env) { _env = env; }
2110
2111 BufferBlob* get_buffer_blob() const { return _buffer_blob; }
2112 void set_buffer_blob(BufferBlob* b) { _buffer_blob = b; }
2113
2114 // Get/set the thread's logging information
2115 CompileLog* log() { return _log; }
2116 void init_log(CompileLog* log) {
2117 // Set once, for good.
2118 assert(_log == NULL, "set only once");
2119 _log = log;
2120 }
2121
2122 void start_idle_timer() { _idle_time.update(); }
2123 jlong idle_time_millis() {
2124 return TimeHelper::counter_to_millis(_idle_time.ticks_since_update());
2125 }
2126
2127 #ifndef PRODUCT
2128 private:
2129 IdealGraphPrinter *_ideal_graph_printer;
2130 public:
2131 IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; }
2132 void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2133 #endif
2134
2135 // Get/set the thread's current task
2136 CompileTask* task() { return _task; }
2137 void set_task(CompileTask* task) { _task = task; }
2138 };
2139
2140 inline CompilerThread* CompilerThread::current() {
2141 return JavaThread::current()->as_CompilerThread();
2142 }
2143
2144 // The active thread queue. It also keeps track of the current used
2145 // thread priorities.
2146 class Threads: AllStatic {
2147 friend class VMStructs;
2148 private:
2149 static JavaThread* _thread_list;
2150 static int _number_of_threads;
2151 static int _number_of_non_daemon_threads;
2152 static int _return_code;
2153 static int _thread_claim_parity;
2154 #ifdef ASSERT
2155 static bool _vm_complete;
2156 static size_t _threads_before_barrier_set;
2157 #endif
2158
2159 static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2160 static void initialize_jsr292_core_classes(TRAPS);
2161
2162 public:
2163 // Thread management
2164 // force_daemon is a concession to JNI, where we may need to add a
2165 // thread to the thread list before allocating its thread object
2166 static void add(JavaThread* p, bool force_daemon = false);
2167 static void remove(JavaThread* p);
2168 static void non_java_threads_do(ThreadClosure* tc);
2169 static void java_threads_do(ThreadClosure* tc);
2170 static void java_threads_and_vm_thread_do(ThreadClosure* tc);
2171 static void threads_do(ThreadClosure* tc);
2172 static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
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
2210 // Apply "f->do_oop" to roots in all threads that
2211 // are part of compiled frames
2212 static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf);
2213
2214 static void convert_hcode_pointers();
2215 static void restore_hcode_pointers();
2216
2217 // Sweeper
2218 static void nmethods_do(CodeBlobClosure* cf);
2219
2220 // RedefineClasses support
2221 static void metadata_do(void f(Metadata*));
2222 static void metadata_handles_do(void f(Metadata*));
2223
2224 #ifdef ASSERT
2225 static bool is_vm_complete() { return _vm_complete; }
2226
2227 static size_t threads_before_barrier_set() {
2228 return _threads_before_barrier_set;
2229 }
2230
2231 static void inc_threads_before_barrier_set() {
2232 ++_threads_before_barrier_set;
2233 }
2234 #endif // ASSERT
2235
2236 // Verification
2237 static void verify();
2238 static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks, bool print_extended_info);
2239 static void print(bool print_stacks, bool internal_format) {
2240 // this function is only used by debug.cpp
2241 print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */, false /* simple format */);
2242 }
2243 static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2244 static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
2245 int buflen, bool* found_current);
2246 static void print_threads_compiling(outputStream* st, char* buf, int buflen);
2247
2248 // Get Java threads that are waiting to enter a monitor.
2249 static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
2250 int count, address monitor);
2251
2252 // Get owning Java thread from the monitor's owner field.
2253 static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
2254 address owner);
2255
2256 // Number of threads on the active threads list
2257 static int number_of_threads() { return _number_of_threads; }
2258 // Number of non-daemon threads on the active threads list
2259 static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; }
2260
2261 // Deoptimizes all frames tied to marked nmethods
2262 static void deoptimized_wrt_marked_nmethods();
2263 };
2264
2265
2266 // Thread iterator
2267 class ThreadClosure: public StackObj {
2268 public:
2269 virtual void do_thread(Thread* thread) = 0;
2270 };
2271
2272 class SignalHandlerMark: public StackObj {
2273 private:
2274 Thread* _thread;
2275 public:
2276 SignalHandlerMark(Thread* t) {
2277 _thread = t;
2278 if (_thread) _thread->enter_signal_handler();
2279 }
2280 ~SignalHandlerMark() {
2281 if (_thread) _thread->leave_signal_handler();
2282 _thread = NULL;
2283 }
2284 };
2285
2286
2287 #endif // SHARE_VM_RUNTIME_THREAD_HPP