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 // Constructor
387 Thread();
388 virtual ~Thread() = 0; // Thread is abstract.
389
390 // Manage Thread::current()
391 void initialize_thread_current();
392 void clear_thread_current(); // TLS cleanup needed before threads terminate
393
394 public:
395 // thread entry point
396 virtual void run();
397
398 // Testers
399 virtual bool is_VM_thread() const { return false; }
400 virtual bool is_Java_thread() const { return false; }
401 virtual bool is_Compiler_thread() const { return false; }
402 virtual bool is_Code_cache_sweeper_thread() const { return false; }
403 virtual bool is_hidden_from_external_view() const { return false; }
404 virtual bool is_jvmti_agent_thread() const { return false; }
405 // True iff the thread can perform GC operations at a safepoint.
406 // Generally will be true only of VM thread and parallel GC WorkGang
407 // threads.
408 virtual bool is_GC_task_thread() const { return false; }
409 virtual bool is_Watcher_thread() const { return false; }
410 virtual bool is_ConcurrentGC_thread() const { return false; }
411 virtual bool is_Named_thread() const { return false; }
412 virtual bool is_Worker_thread() const { return false; }
413
414 // Can this thread make Java upcalls
415 virtual bool can_call_java() const { return false; }
416
417 // Casts
418 virtual WorkerThread* as_Worker_thread() const { return NULL; }
419
420 virtual char* name() const { return (char*)"Unknown thread"; }
421
422 // Returns the current thread (ASSERTS if NULL)
423 static inline Thread* current();
424 // Returns the current thread, or NULL if not attached
425 static inline Thread* current_or_null();
426 // Returns the current thread, or NULL if not attached, and is
427 // safe for use from signal-handlers
428 static inline Thread* current_or_null_safe();
429
430 // Common thread operations
431 #ifdef ASSERT
432 static void check_for_dangling_thread_pointer(Thread *thread);
433 #endif
434 static void set_priority(Thread* thread, ThreadPriority priority);
435 static ThreadPriority get_priority(const Thread* const thread);
436 static void start(Thread* thread);
437 static void interrupt(Thread* thr);
438 static bool is_interrupted(Thread* thr, bool clear_interrupted);
439
440 void set_native_thread_name(const char *name) {
441 assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
442 os::set_native_thread_name(name);
443 }
444
445 ObjectMonitor** omInUseList_addr() { return (ObjectMonitor **)&omInUseList; }
446 Monitor* SR_lock() const { return _SR_lock; }
447
448 bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
449
450 inline void set_suspend_flag(SuspendFlags f);
451 inline void clear_suspend_flag(SuspendFlags f);
452
453 inline void set_has_async_exception();
454 inline void clear_has_async_exception();
455
456 bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
457
458 inline void set_critical_native_unlock();
459 inline void clear_critical_native_unlock();
460
461 inline void set_trace_flag();
462 inline void clear_trace_flag();
463
464 // Support for Unhandled Oop detection
465 // Add the field for both, fastdebug and debug, builds to keep
466 // Thread's fields layout the same.
467 // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
468 #ifdef CHECK_UNHANDLED_OOPS
469 private:
470 UnhandledOops* _unhandled_oops;
471 #elif defined(ASSERT)
472 private:
473 void* _unhandled_oops;
474 #endif
475 #ifdef CHECK_UNHANDLED_OOPS
476 public:
477 UnhandledOops* unhandled_oops() { return _unhandled_oops; }
478 // Mark oop safe for gc. It may be stack allocated but won't move.
479 void allow_unhandled_oop(oop *op) {
480 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
481 }
482 // Clear oops at safepoint so crashes point to unhandled oop violator
483 void clear_unhandled_oops() {
484 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
485 }
486 #endif // CHECK_UNHANDLED_OOPS
487
488 public:
489 #ifndef PRODUCT
490 bool skip_gcalot() { return _skip_gcalot; }
491 void set_skip_gcalot(bool v) { _skip_gcalot = v; }
492 #endif
493
494 // Installs a pending exception to be inserted later
495 static void send_async_exception(oop thread_oop, oop java_throwable);
496
497 // Resource area
498 ResourceArea* resource_area() const { return _resource_area; }
499 void set_resource_area(ResourceArea* area) { _resource_area = area; }
500
501 OSThread* osthread() const { return _osthread; }
502 void set_osthread(OSThread* thread) { _osthread = thread; }
503
504 // JNI handle support
505 JNIHandleBlock* active_handles() const { return _active_handles; }
506 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
507 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
508 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
509
510 // Internal handle support
511 HandleArea* handle_area() const { return _handle_area; }
512 void set_handle_area(HandleArea* area) { _handle_area = area; }
513
514 GrowableArray<Metadata*>* metadata_handles() const { return _metadata_handles; }
515 void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
516
517 // Thread-Local Allocation Buffer (TLAB) support
518 ThreadLocalAllocBuffer& tlab() { return _tlab; }
519 void initialize_tlab() {
520 if (UseTLAB) {
521 tlab().initialize();
522 }
523 }
524
525 jlong allocated_bytes() { return _allocated_bytes; }
526 void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
527 void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
528 inline jlong cooked_allocated_bytes();
529
530 ThreadHeapSampler& heap_sampler() { return _heap_sampler; }
531
532 ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
533
534 JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
535
536 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; }
537
538 // VM operation support
539 int vm_operation_ticket() { return ++_vm_operation_started_count; }
540 int vm_operation_completed_count() { return _vm_operation_completed_count; }
541 void increment_vm_operation_completed_count() { _vm_operation_completed_count++; }
542
543 // For tracking the heavyweight monitor the thread is pending on.
544 ObjectMonitor* current_pending_monitor() {
545 return _current_pending_monitor;
546 }
547 void set_current_pending_monitor(ObjectMonitor* monitor) {
548 _current_pending_monitor = monitor;
549 }
550 void set_current_pending_monitor_is_from_java(bool from_java) {
551 _current_pending_monitor_is_from_java = from_java;
552 }
553 bool current_pending_monitor_is_from_java() {
554 return _current_pending_monitor_is_from_java;
555 }
556
557 // For tracking the ObjectMonitor on which this thread called Object.wait()
558 ObjectMonitor* current_waiting_monitor() {
559 return _current_waiting_monitor;
560 }
561 void set_current_waiting_monitor(ObjectMonitor* monitor) {
562 _current_waiting_monitor = monitor;
563 }
564
565 // GC support
566 // Apply "f->do_oop" to all root oops in "this".
567 // Used by JavaThread::oops_do.
568 // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
569 virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
570
571 // Handles the parallel case for the method below.
572 private:
573 bool claim_oops_do_par_case(int collection_parity);
574 public:
575 // Requires that "collection_parity" is that of the current roots
576 // iteration. If "is_par" is false, sets the parity of "this" to
577 // "collection_parity", and returns "true". If "is_par" is true,
578 // uses an atomic instruction to set the current threads parity to
579 // "collection_parity", if it is not already. Returns "true" iff the
580 // calling thread does the update, this indicates that the calling thread
581 // has claimed the thread's stack as a root groop in the current
582 // collection.
583 bool claim_oops_do(bool is_par, int collection_parity) {
584 if (!is_par) {
585 _oops_do_parity = collection_parity;
586 return true;
587 } else {
588 return claim_oops_do_par_case(collection_parity);
589 }
590 }
591
592 // jvmtiRedefineClasses support
593 void metadata_handles_do(void f(Metadata*));
594
595 // Used by fast lock support
596 virtual bool is_lock_owned(address adr) const;
597
598 // Check if address is in the stack of the thread (not just for locks).
599 // Warning: the method can only be used on the running thread
600 bool is_in_stack(address adr) const;
601 // Check if address is in the usable part of the stack (excludes protected
602 // guard pages)
603 bool is_in_usable_stack(address adr) const;
604
605 // Sets this thread as starting thread. Returns failure if thread
606 // creation fails due to lack of memory, too many threads etc.
607 bool set_as_starting_thread();
608
609 protected:
610 // OS data associated with the thread
611 OSThread* _osthread; // Platform-specific thread information
612
613 // Thread local resource area for temporary allocation within the VM
614 ResourceArea* _resource_area;
615
616 DEBUG_ONLY(ResourceMark* _current_resource_mark;)
617
618 // Thread local handle area for allocation of handles within the VM
619 HandleArea* _handle_area;
620 GrowableArray<Metadata*>* _metadata_handles;
621
622 // Support for stack overflow handling, get_thread, etc.
623 address _stack_base;
624 size_t _stack_size;
625 uintptr_t _self_raw_id; // used by get_thread (mutable)
626 int _lgrp_id;
627
628 volatile void** polling_page_addr() { return &_polling_page; }
629
630 public:
631 // Stack overflow support
632 address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
633 void set_stack_base(address base) { _stack_base = base; }
634 size_t stack_size() const { return _stack_size; }
635 void set_stack_size(size_t size) { _stack_size = size; }
636 address stack_end() const { return stack_base() - stack_size(); }
637 void record_stack_base_and_size();
638
639 bool on_local_stack(address adr) const {
640 // QQQ this has knowledge of direction, ought to be a stack method
641 return (_stack_base >= adr && adr >= stack_end());
642 }
643
644 uintptr_t self_raw_id() { return _self_raw_id; }
645 void set_self_raw_id(uintptr_t value) { _self_raw_id = value; }
646
647 int lgrp_id() const { return _lgrp_id; }
648 void set_lgrp_id(int value) { _lgrp_id = value; }
649
650 // Printing
651 void print_on(outputStream* st, bool print_extended_info) const;
652 virtual void print_on(outputStream* st) const { print_on(st, false); }
653 void print() const { print_on(tty); }
654 virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
655 void print_value_on(outputStream* st) const;
656
657 // Debug-only code
658 #ifdef ASSERT
659 private:
660 // Deadlock detection support for Mutex locks. List of locks own by thread.
661 Monitor* _owned_locks;
662 // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
663 // thus the friendship
664 friend class Mutex;
665 friend class Monitor;
666
667 public:
668 void print_owned_locks_on(outputStream* st) const;
669 void print_owned_locks() const { print_owned_locks_on(tty); }
670 Monitor* owned_locks() const { return _owned_locks; }
671 bool owns_locks() const { return owned_locks() != NULL; }
672 bool owns_locks_but_compiled_lock() const;
673 int oops_do_parity() const { return _oops_do_parity; }
674
675 // Deadlock detection
676 bool allow_allocation() { return _allow_allocation_count == 0; }
677 ResourceMark* current_resource_mark() { return _current_resource_mark; }
678 void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
679 #endif
680
681 void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN;
682
683 private:
684 volatile int _jvmti_env_iteration_count;
685
686 public:
687 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; }
688 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; }
689 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; }
690
691 // Code generation
692 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file); }
693 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line); }
694 static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles); }
695
696 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base); }
697 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size); }
698
699 static ByteSize polling_page_offset() { return byte_offset_of(Thread, _polling_page); }
700
701 static ByteSize tlab_start_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); }
702 static ByteSize tlab_end_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); }
703 static ByteSize tlab_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); }
704 static ByteSize tlab_pf_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); }
705
706 static ByteSize allocated_bytes_offset() { return byte_offset_of(Thread, _allocated_bytes); }
707
708 JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
709
710 public:
711 volatile intptr_t _Stalled;
712 volatile int _TypeTag;
713 ParkEvent * _ParkEvent; // for synchronized()
714 ParkEvent * _SleepEvent; // for Thread.sleep
715 ParkEvent * _MutexEvent; // for native internal Mutex/Monitor
716 ParkEvent * _MuxEvent; // for low-level muxAcquire-muxRelease
717 int NativeSyncRecursion; // diagnostic
718
719 volatile int _OnTrap; // Resume-at IP delta
720 jint _hashStateW; // Marsaglia Shift-XOR thread-local RNG
721 jint _hashStateX; // thread-specific hashCode generator state
722 jint _hashStateY;
723 jint _hashStateZ;
724
725 volatile jint rng[4]; // RNG for spin loop
726
727 // Low-level leaf-lock primitives used to implement synchronization
728 // and native monitor-mutex infrastructure.
729 // Not for general synchronization use.
730 static void SpinAcquire(volatile int * Lock, const char * Name);
731 static void SpinRelease(volatile int * Lock);
732 static void muxAcquire(volatile intptr_t * Lock, const char * Name);
733 static void muxAcquireW(volatile intptr_t * Lock, ParkEvent * ev);
734 static void muxRelease(volatile intptr_t * Lock);
735 };
736
737 // Inline implementation of Thread::current()
738 inline Thread* Thread::current() {
739 Thread* current = current_or_null();
740 assert(current != NULL, "Thread::current() called on detached thread");
741 return current;
742 }
743
744 inline Thread* Thread::current_or_null() {
745 #ifndef USE_LIBRARY_BASED_TLS_ONLY
746 return _thr_current;
747 #else
748 if (ThreadLocalStorage::is_initialized()) {
749 return ThreadLocalStorage::thread();
750 }
751 return NULL;
752 #endif
753 }
754
755 inline Thread* Thread::current_or_null_safe() {
756 if (ThreadLocalStorage::is_initialized()) {
757 return ThreadLocalStorage::thread();
758 }
759 return NULL;
760 }
761
762 class NonJavaThread: public Thread {
763 friend class VMStructs;
764
765 NonJavaThread* volatile _next;
766
767 class List;
768 static List _the_list;
769
770 public:
771 NonJavaThread();
772 ~NonJavaThread();
773
774 class Iterator;
775 };
776
777 // Provides iteration over the list of NonJavaThreads. Because list
778 // management occurs in the NonJavaThread constructor and destructor,
779 // entries in the list may not be fully constructed instances of a
780 // derived class. Threads created after an iterator is constructed
781 // will not be visited by the iterator. The scope of an iterator is a
782 // critical section; there must be no safepoint checks in that scope.
783 class NonJavaThread::Iterator : public StackObj {
784 uint _protect_enter;
785 NonJavaThread* _current;
786
787 // Noncopyable.
788 Iterator(const Iterator&);
789 Iterator& operator=(const Iterator&);
790
791 public:
792 Iterator();
793 ~Iterator();
794
795 bool end() const { return _current == NULL; }
796 NonJavaThread* current() const { return _current; }
797 void step();
798 };
799
800 // Name support for threads. non-JavaThread subclasses with multiple
801 // uniquely named instances should derive from this.
802 class NamedThread: public NonJavaThread {
803 friend class VMStructs;
804 enum {
805 max_name_len = 64
806 };
807 private:
808 char* _name;
809 // log JavaThread being processed by oops_do
810 JavaThread* _processed_thread;
811 uint _gc_id; // The current GC id when a thread takes part in GC
812
813 public:
814 NamedThread();
815 ~NamedThread();
816 // May only be called once per thread.
817 void set_name(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
818 void initialize_named_thread();
819 virtual bool is_Named_thread() const { return true; }
820 virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
821 JavaThread *processed_thread() { return _processed_thread; }
822 void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
823 virtual void print_on(outputStream* st) const;
824
825 void set_gc_id(uint gc_id) { _gc_id = gc_id; }
826 uint gc_id() { return _gc_id; }
827 };
828
829 // Worker threads are named and have an id of an assigned work.
830 class WorkerThread: public NamedThread {
831 private:
832 uint _id;
833 public:
834 WorkerThread() : _id(0) { }
835 virtual bool is_Worker_thread() const { return true; }
836
837 virtual WorkerThread* as_Worker_thread() const {
838 assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
839 return (WorkerThread*) this;
840 }
841
842 void set_id(uint work_id) { _id = work_id; }
843 uint id() const { return _id; }
844 };
845
846 // A single WatcherThread is used for simulating timer interrupts.
847 class WatcherThread: public NonJavaThread {
848 friend class VMStructs;
849 public:
850 virtual void run();
851
852 private:
853 static WatcherThread* _watcher_thread;
854
855 static bool _startable;
856 // volatile due to at least one lock-free read
857 volatile static bool _should_terminate;
858 public:
859 enum SomeConstants {
860 delay_interval = 10 // interrupt delay in milliseconds
861 };
862
863 // Constructor
864 WatcherThread();
865
866 // No destruction allowed
867 ~WatcherThread() {
868 guarantee(false, "WatcherThread deletion must fix the race with VM termination");
869 }
870
871 // Tester
872 bool is_Watcher_thread() const { return true; }
873
874 // Printing
875 char* name() const { return (char*)"VM Periodic Task Thread"; }
876 void print_on(outputStream* st) const;
877 void unpark();
878
879 // Returns the single instance of WatcherThread
880 static WatcherThread* watcher_thread() { return _watcher_thread; }
881
882 // Create and start the single instance of WatcherThread, or stop it on shutdown
883 static void start();
884 static void stop();
885 // Only allow start once the VM is sufficiently initialized
886 // Otherwise the first task to enroll will trigger the start
887 static void make_startable();
888 private:
889 int sleep() const;
890 };
891
892
893 class CompilerThread;
894
895 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
896
897 class JavaThread: public Thread {
898 friend class VMStructs;
899 friend class JVMCIVMStructs;
900 friend class WhiteBox;
901 private:
902 JavaThread* _next; // The next thread in the Threads list
903 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
904 oop _threadObj; // The Java level thread object
905
906 #ifdef ASSERT
907 private:
908 int _java_call_counter;
909
910 public:
911 int java_call_counter() { return _java_call_counter; }
912 void inc_java_call_counter() { _java_call_counter++; }
913 void dec_java_call_counter() {
914 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
915 _java_call_counter--;
916 }
917 private: // restore original namespace restriction
918 #endif // ifdef ASSERT
919
920 #ifndef PRODUCT
921 public:
922 enum {
923 jump_ring_buffer_size = 16
924 };
925 private: // restore original namespace restriction
926 #endif
927
928 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
929
930 ThreadFunction _entry_point;
931
932 JNIEnv _jni_environment;
933
934 // Deopt support
935 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
936
937 intptr_t* _must_deopt_id; // id of frame that needs to be deopted once we
938 // transition out of native
939 CompiledMethod* _deopt_nmethod; // CompiledMethod that is currently being deoptimized
940 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
941 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
942 // Because deoptimization is lazy we must save jvmti requests to set locals
943 // in compiled frames until we deoptimize and we have an interpreter frame.
944 // This holds the pointer to array (yeah like there might be more than one) of
945 // description of compiled vframes that have locals that need to be updated.
946 GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
947
948 // Handshake value for fixing 6243940. We need a place for the i2c
949 // adapter to store the callee Method*. This value is NEVER live
950 // across a gc point so it does NOT have to be gc'd
951 // The handshake is open ended since we can't be certain that it will
952 // be NULLed. This is because we rarely ever see the race and end up
953 // in handle_wrong_method which is the backend of the handshake. See
954 // code in i2c adapters and handle_wrong_method.
955
956 Method* _callee_target;
957
958 // Used to pass back results to the interpreter or generated code running Java code.
959 oop _vm_result; // oop result is GC-preserved
960 Metadata* _vm_result_2; // non-oop result
961
962 // See ReduceInitialCardMarks: this holds the precise space interval of
963 // the most recent slow path allocation for which compiled code has
964 // elided card-marks for performance along the fast-path.
965 MemRegion _deferred_card_mark;
966
967 MonitorChunk* _monitor_chunks; // Contains the off stack monitors
968 // allocated during deoptimization
969 // and by JNI_MonitorEnter/Exit
970
971 // Async. requests support
972 enum AsyncRequests {
973 _no_async_condition = 0,
974 _async_exception,
975 _async_unsafe_access_error
976 };
977 AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
978 oop _pending_async_exception;
979
980 // Safepoint support
981 public: // Expose _thread_state for SafeFetchInt()
982 volatile JavaThreadState _thread_state;
983 private:
984 ThreadSafepointState *_safepoint_state; // Holds information about a thread during a safepoint
985 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
986
987 // JavaThread termination support
988 enum TerminatedTypes {
989 _not_terminated = 0xDEAD - 2,
990 _thread_exiting, // JavaThread::exit() has been called for this thread
991 _thread_terminated, // JavaThread is removed from thread list
992 _vm_exited // JavaThread is still executing native code, but VM is terminated
993 // only VM_Exit can set _vm_exited
994 };
995
996 // In general a JavaThread's _terminated field transitions as follows:
997 //
998 // _not_terminated => _thread_exiting => _thread_terminated
999 //
1000 // _vm_exited is a special value to cover the case of a JavaThread
1001 // executing native code after the VM itself is terminated.
1002 volatile TerminatedTypes _terminated;
1003 // suspend/resume support
1004 volatile bool _suspend_equivalent; // Suspend equivalent condition
1005 jint _in_deopt_handler; // count of deoptimization
1006 // handlers thread is in
1007 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
1008 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
1009 // never locked) when throwing an exception. Used by interpreter only.
1010
1011 // JNI attach states:
1012 enum JNIAttachStates {
1013 _not_attaching_via_jni = 1, // thread is not attaching via JNI
1014 _attaching_via_jni, // thread is attaching via JNI
1015 _attached_via_jni // thread has attached via JNI
1016 };
1017
1018 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
1019 // A native thread that is attaching via JNI starts with a value
1020 // of _attaching_via_jni and transitions to _attached_via_jni.
1021 volatile JNIAttachStates _jni_attach_state;
1022
1023 public:
1024 // State of the stack guard pages for this thread.
1025 enum StackGuardState {
1026 stack_guard_unused, // not needed
1027 stack_guard_reserved_disabled,
1028 stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
1029 stack_guard_enabled // enabled
1030 };
1031
1032 private:
1033
1034 #if INCLUDE_JVMCI
1035 // The _pending_* fields below are used to communicate extra information
1036 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
1037
1038 // Communicates the DeoptReason and DeoptAction of the uncommon trap
1039 int _pending_deoptimization;
1040
1041 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
1042 // before the monitor has been acquired.
1043 bool _pending_monitorenter;
1044
1045 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
1046 bool _pending_transfer_to_interpreter;
1047
1048 // Guard for re-entrant call to JVMCIRuntime::adjust_comp_level
1049 bool _adjusting_comp_level;
1050
1051 // An id of a speculation that JVMCI compiled code can use to further describe and
1052 // uniquely identify the speculative optimization guarded by the uncommon trap
1053 long _pending_failed_speculation;
1054
1055 // These fields are mutually exclusive in terms of live ranges.
1056 union {
1057 // Communicates the pc at which the most recent implicit exception occurred
1058 // from the signal handler to a deoptimization stub.
1059 address _implicit_exception_pc;
1060
1061 // Communicates an alternative call target to an i2c stub from a JavaCall .
1062 address _alternate_call_target;
1063 } _jvmci;
1064
1065 // Support for high precision, thread sensitive counters in JVMCI compiled code.
1066 jlong* _jvmci_counters;
1067
1068 public:
1069 static jlong* _jvmci_old_thread_counters;
1070 static void collect_counters(typeArrayOop array);
1071 private:
1072 #endif // INCLUDE_JVMCI
1073
1074 StackGuardState _stack_guard_state;
1075
1076 // Precompute the limit of the stack as used in stack overflow checks.
1077 // We load it from here to simplify the stack overflow check in assembly.
1078 address _stack_overflow_limit;
1079 address _reserved_stack_activation;
1080
1081 #ifdef _WIN64
1082 // On windows, in the stubGenerator, there's nowhere to save callee saved regs
1083 address _windows_saved_rsi;
1084 address _windows_saved_rdi;
1085 #endif // _WIN64
1086
1087 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1088 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1089 // code)
1090 volatile oop _exception_oop; // Exception thrown in compiled code
1091 volatile address _exception_pc; // PC where exception happened
1092 volatile address _exception_handler_pc; // PC for handler of exception
1093 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
1094
1095 private:
1096 // support for JNI critical regions
1097 jint _jni_active_critical; // count of entries into JNI critical region
1098
1099 // Checked JNI: function name requires exception check
1100 char* _pending_jni_exception_check_fn;
1101
1102 // For deadlock detection.
1103 int _depth_first_number;
1104
1105 // JVMTI PopFrame support
1106 // This is set to popframe_pending to signal that top Java frame should be popped immediately
1107 int _popframe_condition;
1108
1109 // If reallocation of scalar replaced objects fails, we throw OOM
1110 // and during exception propagation, pop the top
1111 // _frames_to_pop_failed_realloc frames, the ones that reference
1112 // failed reallocations.
1113 int _frames_to_pop_failed_realloc;
1114
1115 #ifndef PRODUCT
1116 int _jmp_ring_index;
1117 struct {
1118 // We use intptr_t instead of address so debugger doesn't try and display strings
1119 intptr_t _target;
1120 intptr_t _instruction;
1121 const char* _file;
1122 int _line;
1123 } _jmp_ring[jump_ring_buffer_size];
1124 #endif // PRODUCT
1125
1126 friend class VMThread;
1127 friend class ThreadWaitTransition;
1128 friend class VM_Exit;
1129
1130 void initialize(); // Initialized the instance variables
1131
1132 public:
1133 // Constructor
1134 JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1135 JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1136 ~JavaThread();
1137
1138 #ifdef ASSERT
1139 // verify this JavaThread hasn't be published in the Threads::list yet
1140 void verify_not_published();
1141 #endif
1142
1143 //JNI functiontable getter/setter for JVMTI jni function table interception API.
1144 void set_jni_functions(struct JNINativeInterface_* functionTable) {
1145 _jni_environment.functions = functionTable;
1146 }
1147 struct JNINativeInterface_* get_jni_functions() {
1148 return (struct JNINativeInterface_ *)_jni_environment.functions;
1149 }
1150
1151 // This function is called at thread creation to allow
1152 // platform specific thread variables to be initialized.
1153 void cache_global_variables();
1154
1155 // Executes Shutdown.shutdown()
1156 void invoke_shutdown_hooks();
1157
1158 // Cleanup on thread exit
1159 enum ExitType {
1160 normal_exit,
1161 jni_detach
1162 };
1163 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1164
1165 void cleanup_failed_attach_current_thread();
1166
1167 // Testers
1168 virtual bool is_Java_thread() const { return true; }
1169 virtual bool can_call_java() const { return true; }
1170
1171 // Thread chain operations
1172 JavaThread* next() const { return _next; }
1173 void set_next(JavaThread* p) { _next = p; }
1174
1175 // Thread oop. threadObj() can be NULL for initial JavaThread
1176 // (or for threads attached via JNI)
1177 oop threadObj() const { return _threadObj; }
1178 void set_threadObj(oop p) { _threadObj = p; }
1179
1180 ThreadPriority java_priority() const; // Read from threadObj()
1181
1182 // Prepare thread and add to priority queue. If a priority is
1183 // not specified, use the priority of the thread object. Threads_lock
1184 // must be held while this function is called.
1185 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1186
1187 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
1188 address saved_exception_pc() { return _saved_exception_pc; }
1189
1190
1191 ThreadFunction entry_point() const { return _entry_point; }
1192
1193 // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1194 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1195
1196 // Last frame anchor routines
1197
1198 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
1199
1200 // last_Java_sp
1201 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
1202 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
1203
1204 // last_Java_pc
1205
1206 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
1207
1208 // Safepoint support
1209 #if !(defined(PPC64) || defined(AARCH64))
1210 JavaThreadState thread_state() const { return _thread_state; }
1211 void set_thread_state(JavaThreadState s) { _thread_state = s; }
1212 #else
1213 // Use membars when accessing volatile _thread_state. See
1214 // Threads::create_vm() for size checks.
1215 inline JavaThreadState thread_state() const;
1216 inline void set_thread_state(JavaThreadState s);
1217 #endif
1218 ThreadSafepointState *safepoint_state() const { return _safepoint_state; }
1219 void set_safepoint_state(ThreadSafepointState *state) { _safepoint_state = state; }
1220 bool is_at_poll_safepoint() { return _safepoint_state->is_at_poll_safepoint(); }
1221
1222 // JavaThread termination and lifecycle support:
1223 void smr_delete();
1224 bool on_thread_list() const { return _on_thread_list; }
1225 void set_on_thread_list() { _on_thread_list = true; }
1226
1227 // thread has called JavaThread::exit() or is terminated
1228 bool is_exiting() const;
1229 // thread is terminated (no longer on the threads list); we compare
1230 // against the two non-terminated values so that a freed JavaThread
1231 // will also be considered terminated.
1232 bool check_is_terminated(TerminatedTypes l_terminated) const {
1233 return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1234 }
1235 bool is_terminated() const;
1236 void set_terminated(TerminatedTypes t);
1237 // special for Threads::remove() which is static:
1238 void set_terminated_value();
1239 void block_if_vm_exited();
1240
1241 bool doing_unsafe_access() { return _doing_unsafe_access; }
1242 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
1243
1244 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
1245 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1246
1247 inline void set_polling_page_release(void* poll_value);
1248 inline void set_polling_page(void* poll_value);
1249 inline volatile void* get_polling_page();
1250
1251 private:
1252 // Support for thread handshake operations
1253 HandshakeState _handshake;
1254 public:
1255 void set_handshake_operation(HandshakeOperation* op) {
1256 _handshake.set_operation(this, op);
1257 }
1258
1259 bool has_handshake() const {
1260 return _handshake.has_operation();
1261 }
1262
1263 void cancel_handshake() {
1264 _handshake.cancel(this);
1265 }
1266
1267 void handshake_process_by_self() {
1268 _handshake.process_by_self(this);
1269 }
1270
1271 void handshake_process_by_vmthread() {
1272 _handshake.process_by_vmthread(this);
1273 }
1274
1275 // Suspend/resume support for JavaThread
1276 private:
1277 inline void set_ext_suspended();
1278 inline void clear_ext_suspended();
1279
1280 public:
1281 void java_suspend();
1282 void java_resume();
1283 int java_suspend_self();
1284
1285 void check_and_wait_while_suspended() {
1286 assert(JavaThread::current() == this, "sanity check");
1287
1288 bool do_self_suspend;
1289 do {
1290 // were we externally suspended while we were waiting?
1291 do_self_suspend = handle_special_suspend_equivalent_condition();
1292 if (do_self_suspend) {
1293 // don't surprise the thread that suspended us by returning
1294 java_suspend_self();
1295 set_suspend_equivalent();
1296 }
1297 } while (do_self_suspend);
1298 }
1299 static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1300 // Check for async exception in addition to safepoint and suspend request.
1301 static void check_special_condition_for_native_trans(JavaThread *thread);
1302
1303 // Same as check_special_condition_for_native_trans but finishes the
1304 // transition into thread_in_Java mode so that it can potentially
1305 // block.
1306 static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1307
1308 bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1309 bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1310 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1311 // Warning: is_ext_suspend_completed() may temporarily drop the
1312 // SR_lock to allow the thread to reach a stable thread state if
1313 // it is currently in a transient thread state.
1314 return is_ext_suspend_completed(false /* !called_by_wait */,
1315 SuspendRetryDelay, bits);
1316 }
1317
1318 // We cannot allow wait_for_ext_suspend_completion() to run forever or
1319 // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1320 // passed as the count and delay parameters. Experiments with specific
1321 // calls to wait_for_ext_suspend_completion() can be done by passing
1322 // other values in the code. Experiments with all calls can be done
1323 // via the appropriate -XX options.
1324 bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1325
1326 // test for suspend - most (all?) of these should go away
1327 bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits);
1328
1329 inline void set_external_suspend();
1330 inline void clear_external_suspend();
1331
1332 inline void set_deopt_suspend();
1333 inline void clear_deopt_suspend();
1334 bool is_deopt_suspend() { return (_suspend_flags & _deopt_suspend) != 0; }
1335
1336 bool is_external_suspend() const {
1337 return (_suspend_flags & _external_suspend) != 0;
1338 }
1339 // Whenever a thread transitions from native to vm/java it must suspend
1340 // if external|deopt suspend is present.
1341 bool is_suspend_after_native() const {
1342 return (_suspend_flags & (_external_suspend | _deopt_suspend)) != 0;
1343 }
1344
1345 // external suspend request is completed
1346 bool is_ext_suspended() const {
1347 return (_suspend_flags & _ext_suspended) != 0;
1348 }
1349
1350 bool is_external_suspend_with_lock() const {
1351 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1352 return is_external_suspend();
1353 }
1354
1355 // Special method to handle a pending external suspend request
1356 // when a suspend equivalent condition lifts.
1357 bool handle_special_suspend_equivalent_condition() {
1358 assert(is_suspend_equivalent(),
1359 "should only be called in a suspend equivalence condition");
1360 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1361 bool ret = is_external_suspend();
1362 if (!ret) {
1363 // not about to self-suspend so clear suspend equivalence
1364 clear_suspend_equivalent();
1365 }
1366 // implied else:
1367 // We have a pending external suspend request so we leave the
1368 // suspend_equivalent flag set until java_suspend_self() sets
1369 // the ext_suspended flag and clears the suspend_equivalent
1370 // flag. This insures that wait_for_ext_suspend_completion()
1371 // will return consistent values.
1372 return ret;
1373 }
1374
1375 // utility methods to see if we are doing some kind of suspension
1376 bool is_being_ext_suspended() const {
1377 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1378 return is_ext_suspended() || is_external_suspend();
1379 }
1380
1381 bool is_suspend_equivalent() const { return _suspend_equivalent; }
1382
1383 void set_suspend_equivalent() { _suspend_equivalent = true; }
1384 void clear_suspend_equivalent() { _suspend_equivalent = false; }
1385
1386 // Thread.stop support
1387 void send_thread_stop(oop throwable);
1388 AsyncRequests clear_special_runtime_exit_condition() {
1389 AsyncRequests x = _special_runtime_exit_condition;
1390 _special_runtime_exit_condition = _no_async_condition;
1391 return x;
1392 }
1393
1394 // Are any async conditions present?
1395 bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1396
1397 void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1398
1399 // these next two are also used for self-suspension and async exception support
1400 void handle_special_runtime_exit_condition(bool check_asyncs = true);
1401
1402 // Return true if JavaThread has an asynchronous condition or
1403 // if external suspension is requested.
1404 bool has_special_runtime_exit_condition() {
1405 // Because we don't use is_external_suspend_with_lock
1406 // it is possible that we won't see an asynchronous external suspend
1407 // request that has just gotten started, i.e., SR_lock grabbed but
1408 // _external_suspend field change either not made yet or not visible
1409 // yet. However, this is okay because the request is asynchronous and
1410 // we will see the new flag value the next time through. It's also
1411 // possible that the external suspend request is dropped after
1412 // we have checked is_external_suspend(), we will recheck its value
1413 // under SR_lock in java_suspend_self().
1414 return (_special_runtime_exit_condition != _no_async_condition) ||
1415 is_external_suspend() || is_trace_suspend();
1416 }
1417
1418 void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; }
1419
1420 inline void set_pending_async_exception(oop e);
1421
1422 // Fast-locking support
1423 bool is_lock_owned(address adr) const;
1424
1425 // Accessors for vframe array top
1426 // The linked list of vframe arrays are sorted on sp. This means when we
1427 // unpack the head must contain the vframe array to unpack.
1428 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1429 vframeArray* vframe_array_head() const { return _vframe_array_head; }
1430
1431 // Side structure for deferring update of java frame locals until deopt occurs
1432 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1433 void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1434
1435 // These only really exist to make debugging deopt problems simpler
1436
1437 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1438 vframeArray* vframe_array_last() const { return _vframe_array_last; }
1439
1440 // The special resourceMark used during deoptimization
1441
1442 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
1443 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
1444
1445 intptr_t* must_deopt_id() { return _must_deopt_id; }
1446 void set_must_deopt_id(intptr_t* id) { _must_deopt_id = id; }
1447 void clear_must_deopt_id() { _must_deopt_id = NULL; }
1448
1449 void set_deopt_compiled_method(CompiledMethod* nm) { _deopt_nmethod = nm; }
1450 CompiledMethod* deopt_compiled_method() { return _deopt_nmethod; }
1451
1452 Method* callee_target() const { return _callee_target; }
1453 void set_callee_target (Method* x) { _callee_target = x; }
1454
1455 // Oop results of vm runtime calls
1456 oop vm_result() const { return _vm_result; }
1457 void set_vm_result (oop x) { _vm_result = x; }
1458
1459 Metadata* vm_result_2() const { return _vm_result_2; }
1460 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
1461
1462 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
1463 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
1464
1465 #if INCLUDE_JVMCI
1466 int pending_deoptimization() const { return _pending_deoptimization; }
1467 long pending_failed_speculation() const { return _pending_failed_speculation; }
1468 bool adjusting_comp_level() const { return _adjusting_comp_level; }
1469 void set_adjusting_comp_level(bool b) { _adjusting_comp_level = b; }
1470 bool has_pending_monitorenter() const { return _pending_monitorenter; }
1471 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
1472 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
1473 void set_pending_failed_speculation(long failed_speculation) { _pending_failed_speculation = failed_speculation; }
1474 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1475 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1476 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1477 #endif // INCLUDE_JVMCI
1478
1479 // Exception handling for compiled methods
1480 oop exception_oop() const { return _exception_oop; }
1481 address exception_pc() const { return _exception_pc; }
1482 address exception_handler_pc() const { return _exception_handler_pc; }
1483 bool is_method_handle_return() const { return _is_method_handle_return == 1; }
1484
1485 void set_exception_oop(oop o) { (void)const_cast<oop&>(_exception_oop = o); }
1486 void set_exception_pc(address a) { _exception_pc = a; }
1487 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
1488 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
1489
1490 void clear_exception_oop_and_pc() {
1491 set_exception_oop(NULL);
1492 set_exception_pc(NULL);
1493 }
1494
1495 // Stack overflow support
1496 //
1497 // (small addresses)
1498 //
1499 // -- <-- stack_end() ---
1500 // | |
1501 // | red pages |
1502 // | |
1503 // -- <-- stack_red_zone_base() |
1504 // | |
1505 // | guard
1506 // | yellow pages zone
1507 // | |
1508 // | |
1509 // -- <-- stack_yellow_zone_base() |
1510 // | |
1511 // | |
1512 // | reserved pages |
1513 // | |
1514 // -- <-- stack_reserved_zone_base() --- ---
1515 // /|\ shadow <-- stack_overflow_limit() (somewhere in here)
1516 // | zone
1517 // \|/ size
1518 // some untouched memory ---
1519 //
1520 //
1521 // --
1522 // |
1523 // | shadow zone
1524 // |
1525 // --
1526 // x frame n
1527 // --
1528 // x frame n-1
1529 // x
1530 // --
1531 // ...
1532 //
1533 // --
1534 // x frame 0
1535 // -- <-- stack_base()
1536 //
1537 // (large addresses)
1538 //
1539
1540 private:
1541 // These values are derived from flags StackRedPages, StackYellowPages,
1542 // StackReservedPages and StackShadowPages. The zone size is determined
1543 // ergonomically if page_size > 4K.
1544 static size_t _stack_red_zone_size;
1545 static size_t _stack_yellow_zone_size;
1546 static size_t _stack_reserved_zone_size;
1547 static size_t _stack_shadow_zone_size;
1548 public:
1549 inline size_t stack_available(address cur_sp);
1550
1551 static size_t stack_red_zone_size() {
1552 assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1553 return _stack_red_zone_size;
1554 }
1555 static void set_stack_red_zone_size(size_t s) {
1556 assert(is_aligned(s, os::vm_page_size()),
1557 "We can not protect if the red zone size is not page aligned.");
1558 assert(_stack_red_zone_size == 0, "This should be called only once.");
1559 _stack_red_zone_size = s;
1560 }
1561 address stack_red_zone_base() {
1562 return (address)(stack_end() + stack_red_zone_size());
1563 }
1564 bool in_stack_red_zone(address a) {
1565 return a <= stack_red_zone_base() && a >= stack_end();
1566 }
1567
1568 static size_t stack_yellow_zone_size() {
1569 assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1570 return _stack_yellow_zone_size;
1571 }
1572 static void set_stack_yellow_zone_size(size_t s) {
1573 assert(is_aligned(s, os::vm_page_size()),
1574 "We can not protect if the yellow zone size is not page aligned.");
1575 assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1576 _stack_yellow_zone_size = s;
1577 }
1578
1579 static size_t stack_reserved_zone_size() {
1580 // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1581 return _stack_reserved_zone_size;
1582 }
1583 static void set_stack_reserved_zone_size(size_t s) {
1584 assert(is_aligned(s, os::vm_page_size()),
1585 "We can not protect if the reserved zone size is not page aligned.");
1586 assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1587 _stack_reserved_zone_size = s;
1588 }
1589 address stack_reserved_zone_base() {
1590 return (address)(stack_end() +
1591 (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1592 }
1593 bool in_stack_reserved_zone(address a) {
1594 return (a <= stack_reserved_zone_base()) &&
1595 (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1596 }
1597
1598 static size_t stack_yellow_reserved_zone_size() {
1599 return _stack_yellow_zone_size + _stack_reserved_zone_size;
1600 }
1601 bool in_stack_yellow_reserved_zone(address a) {
1602 return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1603 }
1604
1605 // Size of red + yellow + reserved zones.
1606 static size_t stack_guard_zone_size() {
1607 return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1608 }
1609
1610 static size_t stack_shadow_zone_size() {
1611 assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1612 return _stack_shadow_zone_size;
1613 }
1614 static void set_stack_shadow_zone_size(size_t s) {
1615 // The shadow area is not allocated or protected, so
1616 // it needs not be page aligned.
1617 // But the stack bang currently assumes that it is a
1618 // multiple of page size. This guarantees that the bang
1619 // loop touches all pages in the shadow zone.
1620 // This can be guaranteed differently, as well. E.g., if
1621 // the page size is a multiple of 4K, banging in 4K steps
1622 // suffices to touch all pages. (Some pages are banged
1623 // several times, though.)
1624 assert(is_aligned(s, os::vm_page_size()),
1625 "Stack bang assumes multiple of page size.");
1626 assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1627 _stack_shadow_zone_size = s;
1628 }
1629
1630 void create_stack_guard_pages();
1631 void remove_stack_guard_pages();
1632
1633 void enable_stack_reserved_zone();
1634 void disable_stack_reserved_zone();
1635 void enable_stack_yellow_reserved_zone();
1636 void disable_stack_yellow_reserved_zone();
1637 void enable_stack_red_zone();
1638 void disable_stack_red_zone();
1639
1640 inline bool stack_guard_zone_unused();
1641 inline bool stack_yellow_reserved_zone_disabled();
1642 inline bool stack_reserved_zone_disabled();
1643 inline bool stack_guards_enabled();
1644
1645 address reserved_stack_activation() const { return _reserved_stack_activation; }
1646 void set_reserved_stack_activation(address addr) {
1647 assert(_reserved_stack_activation == stack_base()
1648 || _reserved_stack_activation == NULL
1649 || addr == stack_base(), "Must not be set twice");
1650 _reserved_stack_activation = addr;
1651 }
1652
1653 // Attempt to reguard the stack after a stack overflow may have occurred.
1654 // Returns true if (a) guard pages are not needed on this thread, (b) the
1655 // pages are already guarded, or (c) the pages were successfully reguarded.
1656 // Returns false if there is not enough stack space to reguard the pages, in
1657 // which case the caller should unwind a frame and try again. The argument
1658 // should be the caller's (approximate) sp.
1659 bool reguard_stack(address cur_sp);
1660 // Similar to above but see if current stackpoint is out of the guard area
1661 // and reguard if possible.
1662 bool reguard_stack(void);
1663
1664 address stack_overflow_limit() { return _stack_overflow_limit; }
1665 void set_stack_overflow_limit() {
1666 _stack_overflow_limit =
1667 stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1668 }
1669
1670 // Misc. accessors/mutators
1671 void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; }
1672 void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; }
1673 bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; }
1674
1675 #ifndef PRODUCT
1676 void record_jump(address target, address instr, const char* file, int line);
1677 #endif // PRODUCT
1678
1679 // For assembly stub generation
1680 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
1681 #ifndef PRODUCT
1682 static ByteSize jmp_ring_index_offset() { return byte_offset_of(JavaThread, _jmp_ring_index); }
1683 static ByteSize jmp_ring_offset() { return byte_offset_of(JavaThread, _jmp_ring); }
1684 #endif // PRODUCT
1685 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
1686 static ByteSize pending_jni_exception_check_fn_offset() {
1687 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1688 }
1689 static ByteSize last_Java_sp_offset() {
1690 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1691 }
1692 static ByteSize last_Java_pc_offset() {
1693 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1694 }
1695 static ByteSize frame_anchor_offset() {
1696 return byte_offset_of(JavaThread, _anchor);
1697 }
1698 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
1699 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); }
1700 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); }
1701 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
1702 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
1703 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
1704 #if INCLUDE_JVMCI
1705 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1706 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
1707 static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1708 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1709 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1710 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
1711 #endif // INCLUDE_JVMCI
1712 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
1713 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
1714 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
1715 static ByteSize stack_overflow_limit_offset() { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1716 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1717 static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state); }
1718 static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1719 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
1720
1721 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1722 static ByteSize should_post_on_exceptions_flag_offset() {
1723 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1724 }
1725
1726 #ifdef _WIN64
1727 static ByteSize windows_saved_rsi_offset() { return byte_offset_of(JavaThread, _windows_saved_rsi); }
1728 static ByteSize windows_saved_rdi_offset() { return byte_offset_of(JavaThread, _windows_saved_rdi); }
1729 #endif // _WIN64
1730
1731 // Returns the jni environment for this thread
1732 JNIEnv* jni_environment() { return &_jni_environment; }
1733
1734 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1735 JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1736 // Only return NULL if thread is off the thread list; starting to
1737 // exit should not return NULL.
1738 if (thread_from_jni_env->is_terminated()) {
1739 thread_from_jni_env->block_if_vm_exited();
1740 return NULL;
1741 } else {
1742 return thread_from_jni_env;
1743 }
1744 }
1745
1746 // JNI critical regions. These can nest.
1747 bool in_critical() { return _jni_active_critical > 0; }
1748 bool in_last_critical() { return _jni_active_critical == 1; }
1749 void enter_critical() {
1750 assert(Thread::current() == this ||
1751 (Thread::current()->is_VM_thread() &&
1752 SafepointSynchronize::is_synchronizing()),
1753 "this must be current thread or synchronizing");
1754 _jni_active_critical++;
1755 }
1756 void exit_critical() {
1757 assert(Thread::current() == this, "this must be current thread");
1758 _jni_active_critical--;
1759 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1760 }
1761
1762 // Checked JNI: is the programmer required to check for exceptions, if so specify
1763 // which function name. Returning to a Java frame should implicitly clear the
1764 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1765 // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1766 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1767 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1768 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1769 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1770 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1771
1772 // For deadlock detection
1773 int depth_first_number() { return _depth_first_number; }
1774 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1775
1776 private:
1777 void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1778
1779 public:
1780 MonitorChunk* monitor_chunks() const { return _monitor_chunks; }
1781 void add_monitor_chunk(MonitorChunk* chunk);
1782 void remove_monitor_chunk(MonitorChunk* chunk);
1783 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
1784 void inc_in_deopt_handler() { _in_deopt_handler++; }
1785 void dec_in_deopt_handler() {
1786 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1787 if (_in_deopt_handler > 0) { // robustness
1788 _in_deopt_handler--;
1789 }
1790 }
1791
1792 private:
1793 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1794
1795 public:
1796
1797 // Frame iteration; calls the function f for all frames on the stack
1798 void frames_do(void f(frame*, const RegisterMap*));
1799
1800 // Memory operations
1801 void oops_do(OopClosure* f, CodeBlobClosure* cf);
1802
1803 // Sweeper operations
1804 virtual void nmethods_do(CodeBlobClosure* cf);
1805
1806 // RedefineClasses Support
1807 void metadata_do(void f(Metadata*));
1808
1809 // Misc. operations
1810 char* name() const { return (char*)get_thread_name(); }
1811 void print_on(outputStream* st, bool print_extended_info) const;
1812 void print_on(outputStream* st) const { print_on(st, false); }
1813 void print_value();
1814 void print_thread_state_on(outputStream*) const PRODUCT_RETURN;
1815 void print_thread_state() const PRODUCT_RETURN;
1816 void print_on_error(outputStream* st, char* buf, int buflen) const;
1817 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1818 void verify();
1819 const char* get_thread_name() const;
1820 private:
1821 // factor out low-level mechanics for use in both normal and error cases
1822 const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1823 public:
1824 const char* get_threadgroup_name() const;
1825 const char* get_parent_name() const;
1826
1827 // Accessing frames
1828 frame last_frame() {
1829 _anchor.make_walkable(this);
1830 return pd_last_frame();
1831 }
1832 javaVFrame* last_java_vframe(RegisterMap* reg_map);
1833
1834 // Returns method at 'depth' java or native frames down the stack
1835 // Used for security checks
1836 Klass* security_get_caller_class(int depth);
1837
1838 // Print stack trace in external format
1839 void print_stack_on(outputStream* st);
1840 void print_stack() { print_stack_on(tty); }
1841
1842 // Print stack traces in various internal formats
1843 void trace_stack() PRODUCT_RETURN;
1844 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1845 void trace_frames() PRODUCT_RETURN;
1846 void trace_oops() PRODUCT_RETURN;
1847
1848 // Print an annotated view of the stack frames
1849 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1850 void validate_frame_layout() {
1851 print_frame_layout(0, true);
1852 }
1853
1854 // Returns the number of stack frames on the stack
1855 int depth() const;
1856
1857 // Function for testing deoptimization
1858 void deoptimize();
1859 void make_zombies();
1860
1861 void deoptimized_wrt_marked_nmethods();
1862
1863 public:
1864 // Returns the running thread as a JavaThread
1865 static inline JavaThread* current();
1866
1867 // Returns the active Java thread. Do not use this if you know you are calling
1868 // from a JavaThread, as it's slower than JavaThread::current. If called from
1869 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1870 // operation. You may not want that either.
1871 static JavaThread* active();
1872
1873 inline CompilerThread* as_CompilerThread();
1874
1875 public:
1876 virtual void run();
1877 void thread_main_inner();
1878
1879 private:
1880 // PRIVILEGED STACK
1881 PrivilegedElement* _privileged_stack_top;
1882 GrowableArray<oop>* _array_for_gc;
1883 public:
1884
1885 // Returns the privileged_stack information.
1886 PrivilegedElement* privileged_stack_top() const { return _privileged_stack_top; }
1887 void set_privileged_stack_top(PrivilegedElement *e) { _privileged_stack_top = e; }
1888 void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1889
1890 public:
1891 // Thread local information maintained by JVMTI.
1892 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1893 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1894 // getter is used to get this JavaThread's JvmtiThreadState if it has
1895 // one which means NULL can be returned. JvmtiThreadState::state_for()
1896 // is used to get the specified JavaThread's JvmtiThreadState if it has
1897 // one or it allocates a new JvmtiThreadState for the JavaThread and
1898 // returns it. JvmtiThreadState::state_for() will return NULL only if
1899 // the specified JavaThread is exiting.
1900 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1901 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1902
1903 // JVMTI PopFrame support
1904 // Setting and clearing popframe_condition
1905 // All of these enumerated values are bits. popframe_pending
1906 // indicates that a PopFrame() has been requested and not yet been
1907 // completed. popframe_processing indicates that that PopFrame() is in
1908 // the process of being completed. popframe_force_deopt_reexecution_bit
1909 // indicates that special handling is required when returning to a
1910 // deoptimized caller.
1911 enum PopCondition {
1912 popframe_inactive = 0x00,
1913 popframe_pending_bit = 0x01,
1914 popframe_processing_bit = 0x02,
1915 popframe_force_deopt_reexecution_bit = 0x04
1916 };
1917 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1918 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1919 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1920 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1921 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1922 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1923 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1924 void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1925 #ifdef CC_INTERP
1926 bool pop_frame_pending(void) { return ((_popframe_condition & popframe_pending_bit) != 0); }
1927 void clr_pop_frame_pending(void) { _popframe_condition = popframe_inactive; }
1928 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1929 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
1930 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
1931 #endif
1932
1933 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
1934 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
1935 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
1936
1937 private:
1938 // Saved incoming arguments to popped frame.
1939 // Used only when popped interpreted frame returns to deoptimized frame.
1940 void* _popframe_preserved_args;
1941 int _popframe_preserved_args_size;
1942
1943 public:
1944 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
1945 void* popframe_preserved_args();
1946 ByteSize popframe_preserved_args_size();
1947 WordSize popframe_preserved_args_size_in_words();
1948 void popframe_free_preserved_args();
1949
1950
1951 private:
1952 JvmtiThreadState *_jvmti_thread_state;
1953
1954 // Used by the interpreter in fullspeed mode for frame pop, method
1955 // entry, method exit and single stepping support. This field is
1956 // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
1957 // It can be set to zero asynchronously (i.e., without a VM operation
1958 // or a lock) so we have to be very careful.
1959 int _interp_only_mode;
1960
1961 public:
1962 // used by the interpreter for fullspeed debugging support (see above)
1963 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1964 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
1965 int get_interp_only_mode() { return _interp_only_mode; }
1966 void increment_interp_only_mode() { ++_interp_only_mode; }
1967 void decrement_interp_only_mode() { --_interp_only_mode; }
1968
1969 // support for cached flag that indicates whether exceptions need to be posted for this thread
1970 // if this is false, we can avoid deoptimizing when events are thrown
1971 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1972 private:
1973 int _should_post_on_exceptions_flag;
1974
1975 public:
1976 int should_post_on_exceptions_flag() { return _should_post_on_exceptions_flag; }
1977 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
1978
1979 private:
1980 ThreadStatistics *_thread_stat;
1981
1982 public:
1983 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
1984
1985 // Return a blocker object for which this thread is blocked parking.
1986 oop current_park_blocker();
1987
1988 private:
1989 static size_t _stack_size_at_create;
1990
1991 public:
1992 static inline size_t stack_size_at_create(void) {
1993 return _stack_size_at_create;
1994 }
1995 static inline void set_stack_size_at_create(size_t value) {
1996 _stack_size_at_create = value;
1997 }
1998
1999 // Machine dependent stuff
2000 #include OS_CPU_HEADER(thread)
2001
2002 public:
2003 void set_blocked_on_compilation(bool value) {
2004 _blocked_on_compilation = value;
2005 }
2006
2007 bool blocked_on_compilation() {
2008 return _blocked_on_compilation;
2009 }
2010 protected:
2011 bool _blocked_on_compilation;
2012
2013
2014 // JSR166 per-thread parker
2015 private:
2016 Parker* _parker;
2017 public:
2018 Parker* parker() { return _parker; }
2019
2020 // Biased locking support
2021 private:
2022 GrowableArray<MonitorInfo*>* _cached_monitor_info;
2023 public:
2024 GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
2025 void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
2026
2027 // clearing/querying jni attach status
2028 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
2029 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
2030 inline void set_done_attaching_via_jni();
2031 };
2032
2033 // Inline implementation of JavaThread::current
2034 inline JavaThread* JavaThread::current() {
2035 Thread* thread = Thread::current();
2036 assert(thread->is_Java_thread(), "just checking");
2037 return (JavaThread*)thread;
2038 }
2039
2040 inline CompilerThread* JavaThread::as_CompilerThread() {
2041 assert(is_Compiler_thread(), "just checking");
2042 return (CompilerThread*)this;
2043 }
2044
2045 // Dedicated thread to sweep the code cache
2046 class CodeCacheSweeperThread : public JavaThread {
2047 CompiledMethod* _scanned_compiled_method; // nmethod being scanned by the sweeper
2048 public:
2049 CodeCacheSweeperThread();
2050 // Track the nmethod currently being scanned by the sweeper
2051 void set_scanned_compiled_method(CompiledMethod* cm) {
2052 assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value");
2053 _scanned_compiled_method = cm;
2054 }
2055
2056 // Hide sweeper thread from external view.
2057 bool is_hidden_from_external_view() const { return true; }
2058
2059 bool is_Code_cache_sweeper_thread() const { return true; }
2060
2061 // Prevent GC from unloading _scanned_compiled_method
2062 void oops_do(OopClosure* f, CodeBlobClosure* cf);
2063 void nmethods_do(CodeBlobClosure* cf);
2064 };
2065
2066 // A thread used for Compilation.
2067 class CompilerThread : public JavaThread {
2068 friend class VMStructs;
2069 private:
2070 CompilerCounters* _counters;
2071
2072 ciEnv* _env;
2073 CompileLog* _log;
2074 CompileTask* volatile _task; // print_threads_compiling can read this concurrently.
2075 CompileQueue* _queue;
2076 BufferBlob* _buffer_blob;
2077
2078 AbstractCompiler* _compiler;
2079 TimeStamp _idle_time;
2080
2081 public:
2082
2083 static CompilerThread* current();
2084
2085 CompilerThread(CompileQueue* queue, CompilerCounters* counters);
2086 ~CompilerThread();
2087
2088 bool is_Compiler_thread() const { return true; }
2089
2090 virtual bool can_call_java() const;
2091
2092 // Hide native compiler threads from external view.
2093 bool is_hidden_from_external_view() const { return !can_call_java(); }
2094
2095 void set_compiler(AbstractCompiler* c) { _compiler = c; }
2096 AbstractCompiler* compiler() const { return _compiler; }
2097
2098 CompileQueue* queue() const { return _queue; }
2099 CompilerCounters* counters() const { return _counters; }
2100
2101 // Get/set the thread's compilation environment.
2102 ciEnv* env() { return _env; }
2103 void set_env(ciEnv* env) { _env = env; }
2104
2105 BufferBlob* get_buffer_blob() const { return _buffer_blob; }
2106 void set_buffer_blob(BufferBlob* b) { _buffer_blob = b; }
2107
2108 // Get/set the thread's logging information
2109 CompileLog* log() { return _log; }
2110 void init_log(CompileLog* log) {
2111 // Set once, for good.
2112 assert(_log == NULL, "set only once");
2113 _log = log;
2114 }
2115
2116 void start_idle_timer() { _idle_time.update(); }
2117 jlong idle_time_millis() {
2118 return TimeHelper::counter_to_millis(_idle_time.ticks_since_update());
2119 }
2120
2121 #ifndef PRODUCT
2122 private:
2123 IdealGraphPrinter *_ideal_graph_printer;
2124 public:
2125 IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; }
2126 void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2127 #endif
2128
2129 // Get/set the thread's current task
2130 CompileTask* task() { return _task; }
2131 void set_task(CompileTask* task) { _task = task; }
2132 };
2133
2134 inline CompilerThread* CompilerThread::current() {
2135 return JavaThread::current()->as_CompilerThread();
2136 }
2137
2138 // The active thread queue. It also keeps track of the current used
2139 // thread priorities.
2140 class Threads: AllStatic {
2141 friend class VMStructs;
2142 private:
2143 static JavaThread* _thread_list;
2144 static int _number_of_threads;
2145 static int _number_of_non_daemon_threads;
2146 static int _return_code;
2147 static int _thread_claim_parity;
2148 #ifdef ASSERT
2149 static bool _vm_complete;
2150 static size_t _threads_before_barrier_set;
2151 #endif
2152
2153 static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2154 static void initialize_jsr292_core_classes(TRAPS);
2155
2156 public:
2157 // Thread management
2158 // force_daemon is a concession to JNI, where we may need to add a
2159 // thread to the thread list before allocating its thread object
2160 static void add(JavaThread* p, bool force_daemon = false);
2161 static void remove(JavaThread* p);
2162 static void non_java_threads_do(ThreadClosure* tc);
2163 static void java_threads_do(ThreadClosure* tc);
2164 static void java_threads_and_vm_thread_do(ThreadClosure* tc);
2165 static void threads_do(ThreadClosure* tc);
2166 static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
2167
2168 // Initializes the vm and creates the vm thread
2169 static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
2170 static void convert_vm_init_libraries_to_agents();
2171 static void create_vm_init_libraries();
2172 static void create_vm_init_agents();
2173 static void shutdown_vm_agents();
2174 static bool destroy_vm();
2175 // Supported VM versions via JNI
2176 // Includes JNI_VERSION_1_1
2177 static jboolean is_supported_jni_version_including_1_1(jint version);
2178 // Does not include JNI_VERSION_1_1
2179 static jboolean is_supported_jni_version(jint version);
2180
2181 // The "thread claim parity" provides a way for threads to be claimed
2182 // by parallel worker tasks.
2183 //
2184 // Each thread contains a a "parity" field. A task will claim the
2185 // thread only if its parity field is the same as the global parity,
2186 // which is updated by calling change_thread_claim_parity().
2187 //
2188 // For this to work change_thread_claim_parity() needs to be called
2189 // exactly once in sequential code before starting parallel tasks
2190 // that should claim threads.
2191 //
2192 // New threads get their parity set to 0 and change_thread_claim_parity()
2193 // never set the global parity to 0.
2194 static int thread_claim_parity() { return _thread_claim_parity; }
2195 static void change_thread_claim_parity();
2196 static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
2197
2198 // Apply "f->do_oop" to all root oops in all threads.
2199 // This version may only be called by sequential code.
2200 static void oops_do(OopClosure* f, CodeBlobClosure* cf);
2201 // This version may be called by sequential or parallel code.
2202 static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
2203
2204 // Apply "f->do_oop" to roots in all threads that
2205 // are part of compiled frames
2206 static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf);
2207
2208 static void convert_hcode_pointers();
2209 static void restore_hcode_pointers();
2210
2211 // Sweeper
2212 static void nmethods_do(CodeBlobClosure* cf);
2213
2214 // RedefineClasses support
2215 static void metadata_do(void f(Metadata*));
2216 static void metadata_handles_do(void f(Metadata*));
2217
2218 #ifdef ASSERT
2219 static bool is_vm_complete() { return _vm_complete; }
2220
2221 static size_t threads_before_barrier_set() {
2222 return _threads_before_barrier_set;
2223 }
2224
2225 static void inc_threads_before_barrier_set() {
2226 ++_threads_before_barrier_set;
2227 }
2228 #endif // ASSERT
2229
2230 // Verification
2231 static void verify();
2232 static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks, bool print_extended_info);
2233 static void print(bool print_stacks, bool internal_format) {
2234 // this function is only used by debug.cpp
2235 print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */, false /* simple format */);
2236 }
2237 static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2238 static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
2239 int buflen, bool* found_current);
2240 static void print_threads_compiling(outputStream* st, char* buf, int buflen);
2241
2242 // Get Java threads that are waiting to enter a monitor.
2243 static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
2244 int count, address monitor);
2245
2246 // Get owning Java thread from the monitor's owner field.
2247 static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
2248 address owner);
2249
2250 // Number of threads on the active threads list
2251 static int number_of_threads() { return _number_of_threads; }
2252 // Number of non-daemon threads on the active threads list
2253 static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; }
2254
2255 // Deoptimizes all frames tied to marked nmethods
2256 static void deoptimized_wrt_marked_nmethods();
2257 };
2258
2259
2260 // Thread iterator
2261 class ThreadClosure: public StackObj {
2262 public:
2263 virtual void do_thread(Thread* thread) = 0;
2264 };
2265
2266 class SignalHandlerMark: public StackObj {
2267 private:
2268 Thread* _thread;
2269 public:
2270 SignalHandlerMark(Thread* t) {
2271 _thread = t;
2272 if (_thread) _thread->enter_signal_handler();
2273 }
2274 ~SignalHandlerMark() {
2275 if (_thread) _thread->leave_signal_handler();
2276 _thread = NULL;
2277 }
2278 };
2279
2280
2281 #endif // SHARE_VM_RUNTIME_THREAD_HPP