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