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