1 /*
2 * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_VM_RUNTIME_THREAD_HPP
26 #define SHARE_VM_RUNTIME_THREAD_HPP
27
28 #include "jni.h"
29 #include "gc/shared/gcThreadLocalData.hpp"
30 #include "gc/shared/threadLocalAllocBuffer.hpp"
31 #include "memory/allocation.hpp"
32 #include "oops/oop.hpp"
33 #include "prims/jvmtiExport.hpp"
34 #include "runtime/frame.hpp"
35 #include "runtime/globals.hpp"
36 #include "runtime/handshake.hpp"
37 #include "runtime/javaFrameAnchor.hpp"
38 #include "runtime/jniHandles.hpp"
39 #include "runtime/mutexLocker.hpp"
40 #include "runtime/os.hpp"
41 #include "runtime/osThread.hpp"
42 #include "runtime/park.hpp"
43 #include "runtime/safepoint.hpp"
44 #include "runtime/stubRoutines.hpp"
45 #include "runtime/threadLocalStorage.hpp"
46 #include "runtime/unhandledOops.hpp"
47 #include "trace/traceBackend.hpp"
48 #include "trace/traceMacros.hpp"
49 #include "utilities/align.hpp"
50 #include "utilities/exceptions.hpp"
51 #include "utilities/macros.hpp"
52 #ifdef ZERO
53 # include "stack_zero.hpp"
54 #endif
55
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 mutable TRACE_DATA _trace_data; // Thread-local data for tracing
349
350 int _vm_operation_started_count; // VM_Operation support
351 int _vm_operation_completed_count; // VM_Operation support
352
353 ObjectMonitor* _current_pending_monitor; // ObjectMonitor this thread
354 // is waiting to lock
355 bool _current_pending_monitor_is_from_java; // locking is from Java code
356
357 // ObjectMonitor on which this thread called Object.wait()
358 ObjectMonitor* _current_waiting_monitor;
359
360 // Private thread-local objectmonitor list - a simple cache organized as a SLL.
361 public:
362 ObjectMonitor* omFreeList;
363 int omFreeCount; // length of omFreeList
364 int omFreeProvision; // reload chunk size
365 ObjectMonitor* omInUseList; // SLL to track monitors in circulation
366 int omInUseCount; // length of omInUseList
367
368 #ifdef ASSERT
369 private:
370 bool _visited_for_critical_count;
371
372 public:
373 void set_visited_for_critical_count(bool z) { _visited_for_critical_count = z; }
374 bool was_visited_for_critical_count() const { return _visited_for_critical_count; }
375 #endif
376
377 public:
378 enum {
379 is_definitely_current_thread = true
380 };
381
382 // Constructor
383 Thread();
384 virtual ~Thread();
385
386 // Manage Thread::current()
387 void initialize_thread_current();
388 void clear_thread_current(); // TLS cleanup needed before threads terminate
389
390 public:
391 // thread entry point
392 virtual void run();
393
394 // Testers
395 virtual bool is_VM_thread() const { return false; }
396 virtual bool is_Java_thread() const { return false; }
397 virtual bool is_Compiler_thread() const { return false; }
398 virtual bool is_Code_cache_sweeper_thread() const { return false; }
399 virtual bool is_hidden_from_external_view() const { return false; }
400 virtual bool is_jvmti_agent_thread() const { return false; }
401 // True iff the thread can perform GC operations at a safepoint.
402 // Generally will be true only of VM thread and parallel GC WorkGang
403 // threads.
404 virtual bool is_GC_task_thread() const { return false; }
405 virtual bool is_Watcher_thread() const { return false; }
406 virtual bool is_ConcurrentGC_thread() const { return false; }
407 virtual bool is_Named_thread() const { return false; }
408 virtual bool is_Worker_thread() const { return false; }
409
410 // Can this thread make Java upcalls
411 virtual bool can_call_java() const { return false; }
412
413 // Casts
414 virtual WorkerThread* as_Worker_thread() const { return NULL; }
415
416 virtual char* name() const { return (char*)"Unknown thread"; }
417
418 // Returns the current thread (ASSERTS if NULL)
419 static inline Thread* current();
420 // Returns the current thread, or NULL if not attached
421 static inline Thread* current_or_null();
422 // Returns the current thread, or NULL if not attached, and is
423 // safe for use from signal-handlers
424 static inline Thread* current_or_null_safe();
425
426 // Common thread operations
427 #ifdef ASSERT
428 static void check_for_dangling_thread_pointer(Thread *thread);
429 #endif
430 static void set_priority(Thread* thread, ThreadPriority priority);
431 static ThreadPriority get_priority(const Thread* const thread);
432 static void start(Thread* thread);
433 static void interrupt(Thread* thr);
434 static bool is_interrupted(Thread* thr, bool clear_interrupted);
435
436 void set_native_thread_name(const char *name) {
437 assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
438 os::set_native_thread_name(name);
439 }
440
441 ObjectMonitor** omInUseList_addr() { return (ObjectMonitor **)&omInUseList; }
442 Monitor* SR_lock() const { return _SR_lock; }
443
444 bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
445
446 inline void set_suspend_flag(SuspendFlags f);
447 inline void clear_suspend_flag(SuspendFlags f);
448
449 inline void set_has_async_exception();
450 inline void clear_has_async_exception();
451
452 bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
453
454 inline void set_critical_native_unlock();
455 inline void clear_critical_native_unlock();
456
457 inline void set_trace_flag();
458 inline void clear_trace_flag();
459
460 // Support for Unhandled Oop detection
461 // Add the field for both, fastdebug and debug, builds to keep
462 // Thread's fields layout the same.
463 // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
464 #ifdef CHECK_UNHANDLED_OOPS
465 private:
466 UnhandledOops* _unhandled_oops;
467 #elif defined(ASSERT)
468 private:
469 void* _unhandled_oops;
470 #endif
471 #ifdef CHECK_UNHANDLED_OOPS
472 public:
473 UnhandledOops* unhandled_oops() { return _unhandled_oops; }
474 // Mark oop safe for gc. It may be stack allocated but won't move.
475 void allow_unhandled_oop(oop *op) {
476 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
477 }
478 // Clear oops at safepoint so crashes point to unhandled oop violator
479 void clear_unhandled_oops() {
480 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
481 }
482 #endif // CHECK_UNHANDLED_OOPS
483
484 public:
485 #ifndef PRODUCT
486 bool skip_gcalot() { return _skip_gcalot; }
487 void set_skip_gcalot(bool v) { _skip_gcalot = v; }
488 #endif
489
490 // Installs a pending exception to be inserted later
491 static void send_async_exception(oop thread_oop, oop java_throwable);
492
493 // Resource area
494 ResourceArea* resource_area() const { return _resource_area; }
495 void set_resource_area(ResourceArea* area) { _resource_area = area; }
496
497 OSThread* osthread() const { return _osthread; }
498 void set_osthread(OSThread* thread) { _osthread = thread; }
499
500 // JNI handle support
501 JNIHandleBlock* active_handles() const { return _active_handles; }
502 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
503 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
504 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
505
506 // Internal handle support
507 HandleArea* handle_area() const { return _handle_area; }
508 void set_handle_area(HandleArea* area) { _handle_area = area; }
509
510 GrowableArray<Metadata*>* metadata_handles() const { return _metadata_handles; }
511 void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
512
513 // Thread-Local Allocation Buffer (TLAB) support
514 ThreadLocalAllocBuffer& tlab() { return _tlab; }
515 void initialize_tlab() {
516 if (UseTLAB) {
517 tlab().initialize();
518 }
519 }
520
521 jlong allocated_bytes() { return _allocated_bytes; }
522 void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
523 void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
524 inline jlong cooked_allocated_bytes();
525
526 TRACE_DEFINE_THREAD_TRACE_DATA_OFFSET;
527 TRACE_DATA* trace_data() const { return &_trace_data; }
528 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; }
529
530 // VM operation support
531 int vm_operation_ticket() { return ++_vm_operation_started_count; }
532 int vm_operation_completed_count() { return _vm_operation_completed_count; }
533 void increment_vm_operation_completed_count() { _vm_operation_completed_count++; }
534
535 // For tracking the heavyweight monitor the thread is pending on.
536 ObjectMonitor* current_pending_monitor() {
537 return _current_pending_monitor;
538 }
539 void set_current_pending_monitor(ObjectMonitor* monitor) {
540 _current_pending_monitor = monitor;
541 }
542 void set_current_pending_monitor_is_from_java(bool from_java) {
543 _current_pending_monitor_is_from_java = from_java;
544 }
545 bool current_pending_monitor_is_from_java() {
546 return _current_pending_monitor_is_from_java;
547 }
548
549 // For tracking the ObjectMonitor on which this thread called Object.wait()
550 ObjectMonitor* current_waiting_monitor() {
551 return _current_waiting_monitor;
552 }
553 void set_current_waiting_monitor(ObjectMonitor* monitor) {
554 _current_waiting_monitor = monitor;
555 }
556
557 // GC support
558 // Apply "f->do_oop" to all root oops in "this".
559 // Used by JavaThread::oops_do.
560 // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
561 virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
562
563 // Handles the parallel case for the method below.
564 private:
565 bool claim_oops_do_par_case(int collection_parity);
566 public:
567 // Requires that "collection_parity" is that of the current roots
568 // iteration. If "is_par" is false, sets the parity of "this" to
569 // "collection_parity", and returns "true". If "is_par" is true,
570 // uses an atomic instruction to set the current threads parity to
571 // "collection_parity", if it is not already. Returns "true" iff the
572 // calling thread does the update, this indicates that the calling thread
573 // has claimed the thread's stack as a root groop in the current
574 // collection.
575 bool claim_oops_do(bool is_par, int collection_parity) {
576 if (!is_par) {
577 _oops_do_parity = collection_parity;
578 return true;
579 } else {
580 return claim_oops_do_par_case(collection_parity);
581 }
582 }
583
584 // jvmtiRedefineClasses support
585 void metadata_handles_do(void f(Metadata*));
586
587 // Used by fast lock support
588 virtual bool is_lock_owned(address adr) const;
589
590 // Check if address is in the stack of the thread (not just for locks).
591 // Warning: the method can only be used on the running thread
592 bool is_in_stack(address adr) const;
593 // Check if address is in the usable part of the stack (excludes protected
594 // guard pages)
595 bool is_in_usable_stack(address adr) const;
596
597 // Sets this thread as starting thread. Returns failure if thread
598 // creation fails due to lack of memory, too many threads etc.
599 bool set_as_starting_thread();
600
601 protected:
602 // OS data associated with the thread
603 OSThread* _osthread; // Platform-specific thread information
604
605 // Thread local resource area for temporary allocation within the VM
606 ResourceArea* _resource_area;
607
608 DEBUG_ONLY(ResourceMark* _current_resource_mark;)
609
610 // Thread local handle area for allocation of handles within the VM
611 HandleArea* _handle_area;
612 GrowableArray<Metadata*>* _metadata_handles;
613
614 // Support for stack overflow handling, get_thread, etc.
615 address _stack_base;
616 size_t _stack_size;
617 uintptr_t _self_raw_id; // used by get_thread (mutable)
618 int _lgrp_id;
619
620 volatile void** polling_page_addr() { return &_polling_page; }
621
622 public:
623 // Stack overflow support
624 address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
625 void set_stack_base(address base) { _stack_base = base; }
626 size_t stack_size() const { return _stack_size; }
627 void set_stack_size(size_t size) { _stack_size = size; }
628 address stack_end() const { return stack_base() - stack_size(); }
629 void record_stack_base_and_size();
630
631 bool on_local_stack(address adr) const {
632 // QQQ this has knowledge of direction, ought to be a stack method
633 return (_stack_base >= adr && adr >= stack_end());
634 }
635
636 uintptr_t self_raw_id() { return _self_raw_id; }
637 void set_self_raw_id(uintptr_t value) { _self_raw_id = value; }
638
639 int lgrp_id() const { return _lgrp_id; }
640 void set_lgrp_id(int value) { _lgrp_id = value; }
641
642 // Printing
643 virtual void print_on(outputStream* st) const;
644 virtual void print_nested_threads_hazard_ptrs_on(outputStream* st) const;
645 void print() const { print_on(tty); }
646 virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
647 void print_value_on(outputStream* st) const;
648
649 // Debug-only code
650 #ifdef ASSERT
651 private:
652 // Deadlock detection support for Mutex locks. List of locks own by thread.
653 Monitor* _owned_locks;
654 // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
655 // thus the friendship
656 friend class Mutex;
657 friend class Monitor;
658
659 public:
660 void print_owned_locks_on(outputStream* st) const;
661 void print_owned_locks() const { print_owned_locks_on(tty); }
662 Monitor* owned_locks() const { return _owned_locks; }
663 bool owns_locks() const { return owned_locks() != NULL; }
664 bool owns_locks_but_compiled_lock() const;
665 int oops_do_parity() const { return _oops_do_parity; }
666
667 // Deadlock detection
668 bool allow_allocation() { return _allow_allocation_count == 0; }
669 ResourceMark* current_resource_mark() { return _current_resource_mark; }
670 void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
671 #endif
672
673 void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN;
674
675 private:
676 volatile int _jvmti_env_iteration_count;
677
678 public:
679 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; }
680 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; }
681 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; }
682
683 // Code generation
684 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file); }
685 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line); }
686 static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles); }
687
688 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base); }
689 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size); }
690
691 static ByteSize polling_page_offset() { return byte_offset_of(Thread, _polling_page); }
692
693 #define TLAB_FIELD_OFFSET(name) \
694 static ByteSize tlab_##name##_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::name##_offset(); }
695
696 TLAB_FIELD_OFFSET(start)
697 TLAB_FIELD_OFFSET(end)
698 TLAB_FIELD_OFFSET(top)
699 TLAB_FIELD_OFFSET(pf_top)
700 TLAB_FIELD_OFFSET(size) // desired_size
701 TLAB_FIELD_OFFSET(refill_waste_limit)
702 TLAB_FIELD_OFFSET(number_of_refills)
703 TLAB_FIELD_OFFSET(fast_refill_waste)
704 TLAB_FIELD_OFFSET(slow_allocations)
705
706 #undef TLAB_FIELD_OFFSET
707
708 static ByteSize allocated_bytes_offset() { return byte_offset_of(Thread, _allocated_bytes); }
709
710 public:
711 volatile intptr_t _Stalled;
712 volatile int _TypeTag;
713 ParkEvent * _ParkEvent; // for synchronized()
714 ParkEvent * _SleepEvent; // for Thread.sleep
715 ParkEvent * _MutexEvent; // for native internal Mutex/Monitor
716 ParkEvent * _MuxEvent; // for low-level muxAcquire-muxRelease
717 int NativeSyncRecursion; // diagnostic
718
719 volatile int _OnTrap; // Resume-at IP delta
720 jint _hashStateW; // Marsaglia Shift-XOR thread-local RNG
721 jint _hashStateX; // thread-specific hashCode generator state
722 jint _hashStateY;
723 jint _hashStateZ;
724 void * _schedctl;
725
726
727 volatile jint rng[4]; // RNG for spin loop
728
729 // Low-level leaf-lock primitives used to implement synchronization
730 // and native monitor-mutex infrastructure.
731 // Not for general synchronization use.
732 static void SpinAcquire(volatile int * Lock, const char * Name);
733 static void SpinRelease(volatile int * Lock);
734 static void muxAcquire(volatile intptr_t * Lock, const char * Name);
735 static void muxAcquireW(volatile intptr_t * Lock, ParkEvent * ev);
736 static void muxRelease(volatile intptr_t * Lock);
737 };
738
739 // Inline implementation of Thread::current()
740 inline Thread* Thread::current() {
741 Thread* current = current_or_null();
742 assert(current != NULL, "Thread::current() called on detached thread");
743 return current;
744 }
745
746 inline Thread* Thread::current_or_null() {
747 #ifndef USE_LIBRARY_BASED_TLS_ONLY
748 return _thr_current;
749 #else
750 if (ThreadLocalStorage::is_initialized()) {
751 return ThreadLocalStorage::thread();
752 }
753 return NULL;
754 #endif
755 }
756
757 inline Thread* Thread::current_or_null_safe() {
758 if (ThreadLocalStorage::is_initialized()) {
759 return ThreadLocalStorage::thread();
760 }
761 return NULL;
762 }
763
764 // Name support for threads. non-JavaThread subclasses with multiple
765 // uniquely named instances should derive from this.
766 class NamedThread: public Thread {
767 friend class VMStructs;
768 enum {
769 max_name_len = 64
770 };
771 private:
772 char* _name;
773 // log JavaThread being processed by oops_do
774 JavaThread* _processed_thread;
775 uint _gc_id; // The current GC id when a thread takes part in GC
776
777 public:
778 NamedThread();
779 ~NamedThread();
780 // May only be called once per thread.
781 void set_name(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
782 void initialize_named_thread();
783 virtual bool is_Named_thread() const { return true; }
784 virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
785 JavaThread *processed_thread() { return _processed_thread; }
786 void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
787 virtual void print_on(outputStream* st) const;
788
789 void set_gc_id(uint gc_id) { _gc_id = gc_id; }
790 uint gc_id() { return _gc_id; }
791 };
792
793 // Worker threads are named and have an id of an assigned work.
794 class WorkerThread: public NamedThread {
795 private:
796 uint _id;
797 public:
798 WorkerThread() : _id(0) { }
799 virtual bool is_Worker_thread() const { return true; }
800
801 virtual WorkerThread* as_Worker_thread() const {
802 assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
803 return (WorkerThread*) this;
804 }
805
806 void set_id(uint work_id) { _id = work_id; }
807 uint id() const { return _id; }
808 };
809
810 // A single WatcherThread is used for simulating timer interrupts.
811 class WatcherThread: public Thread {
812 friend class VMStructs;
813 public:
814 virtual void run();
815
816 private:
817 static WatcherThread* _watcher_thread;
818
819 static bool _startable;
820 // volatile due to at least one lock-free read
821 volatile static bool _should_terminate;
822 public:
823 enum SomeConstants {
824 delay_interval = 10 // interrupt delay in milliseconds
825 };
826
827 // Constructor
828 WatcherThread();
829
830 // No destruction allowed
831 ~WatcherThread() {
832 guarantee(false, "WatcherThread deletion must fix the race with VM termination");
833 }
834
835 // Tester
836 bool is_Watcher_thread() const { return true; }
837
838 // Printing
839 char* name() const { return (char*)"VM Periodic Task Thread"; }
840 void print_on(outputStream* st) const;
841 void unpark();
842
843 // Returns the single instance of WatcherThread
844 static WatcherThread* watcher_thread() { return _watcher_thread; }
845
846 // Create and start the single instance of WatcherThread, or stop it on shutdown
847 static void start();
848 static void stop();
849 // Only allow start once the VM is sufficiently initialized
850 // Otherwise the first task to enroll will trigger the start
851 static void make_startable();
852 private:
853 int sleep() const;
854 };
855
856
857 class CompilerThread;
858
859 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
860
861 class JavaThread: public Thread {
862 friend class VMStructs;
863 friend class JVMCIVMStructs;
864 friend class WhiteBox;
865 private:
866 JavaThread* _next; // The next thread in the Threads list
867 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
868 oop _threadObj; // The Java level thread object
869
870 #ifdef ASSERT
871 private:
872 int _java_call_counter;
873
874 public:
875 int java_call_counter() { return _java_call_counter; }
876 void inc_java_call_counter() { _java_call_counter++; }
877 void dec_java_call_counter() {
878 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
879 _java_call_counter--;
880 }
881 private: // restore original namespace restriction
882 #endif // ifdef ASSERT
883
884 #ifndef PRODUCT
885 public:
886 enum {
887 jump_ring_buffer_size = 16
888 };
889 private: // restore original namespace restriction
890 #endif
891
892 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
893
894 ThreadFunction _entry_point;
895
896 JNIEnv _jni_environment;
897
898 // Deopt support
899 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
900
901 intptr_t* _must_deopt_id; // id of frame that needs to be deopted once we
902 // transition out of native
903 CompiledMethod* _deopt_nmethod; // CompiledMethod that is currently being deoptimized
904 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
905 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
906 // Because deoptimization is lazy we must save jvmti requests to set locals
907 // in compiled frames until we deoptimize and we have an interpreter frame.
908 // This holds the pointer to array (yeah like there might be more than one) of
909 // description of compiled vframes that have locals that need to be updated.
910 GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
911
912 // Handshake value for fixing 6243940. We need a place for the i2c
913 // adapter to store the callee Method*. This value is NEVER live
914 // across a gc point so it does NOT have to be gc'd
915 // The handshake is open ended since we can't be certain that it will
916 // be NULLed. This is because we rarely ever see the race and end up
917 // in handle_wrong_method which is the backend of the handshake. See
918 // code in i2c adapters and handle_wrong_method.
919
920 Method* _callee_target;
921
922 // Used to pass back results to the interpreter or generated code running Java code.
923 oop _vm_result; // oop result is GC-preserved
924 Metadata* _vm_result_2; // non-oop result
925
926 // See ReduceInitialCardMarks: this holds the precise space interval of
927 // the most recent slow path allocation for which compiled code has
928 // elided card-marks for performance along the fast-path.
929 MemRegion _deferred_card_mark;
930
931 MonitorChunk* _monitor_chunks; // Contains the off stack monitors
932 // allocated during deoptimization
933 // and by JNI_MonitorEnter/Exit
934
935 // Async. requests support
936 enum AsyncRequests {
937 _no_async_condition = 0,
938 _async_exception,
939 _async_unsafe_access_error
940 };
941 AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
942 oop _pending_async_exception;
943
944 // Safepoint support
945 public: // Expose _thread_state for SafeFetchInt()
946 volatile JavaThreadState _thread_state;
947 private:
948 ThreadSafepointState *_safepoint_state; // Holds information about a thread during a safepoint
949 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
950
951 // JavaThread termination support
952 enum TerminatedTypes {
953 _not_terminated = 0xDEAD - 2,
954 _thread_exiting, // JavaThread::exit() has been called for this thread
955 _thread_terminated, // JavaThread is removed from thread list
956 _vm_exited // JavaThread is still executing native code, but VM is terminated
957 // only VM_Exit can set _vm_exited
958 };
959
960 // In general a JavaThread's _terminated field transitions as follows:
961 //
962 // _not_terminated => _thread_exiting => _thread_terminated
963 //
964 // _vm_exited is a special value to cover the case of a JavaThread
965 // executing native code after the VM itself is terminated.
966 volatile TerminatedTypes _terminated;
967 // suspend/resume support
968 volatile bool _suspend_equivalent; // Suspend equivalent condition
969 jint _in_deopt_handler; // count of deoptimization
970 // handlers thread is in
971 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
972 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
973 // never locked) when throwing an exception. Used by interpreter only.
974
975 // JNI attach states:
976 enum JNIAttachStates {
977 _not_attaching_via_jni = 1, // thread is not attaching via JNI
978 _attaching_via_jni, // thread is attaching via JNI
979 _attached_via_jni // thread has attached via JNI
980 };
981
982 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
983 // A native thread that is attaching via JNI starts with a value
984 // of _attaching_via_jni and transitions to _attached_via_jni.
985 volatile JNIAttachStates _jni_attach_state;
986
987 public:
988 // State of the stack guard pages for this thread.
989 enum StackGuardState {
990 stack_guard_unused, // not needed
991 stack_guard_reserved_disabled,
992 stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
993 stack_guard_enabled // enabled
994 };
995
996 private:
997
998 #if INCLUDE_JVMCI
999 // The _pending_* fields below are used to communicate extra information
1000 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
1001
1002 // Communicates the DeoptReason and DeoptAction of the uncommon trap
1003 int _pending_deoptimization;
1004
1005 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
1006 // before the monitor has been acquired.
1007 bool _pending_monitorenter;
1008
1009 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
1010 bool _pending_transfer_to_interpreter;
1011
1012 // Guard for re-entrant call to JVMCIRuntime::adjust_comp_level
1013 bool _adjusting_comp_level;
1014
1015 // An object that JVMCI compiled code can use to further describe and
1016 // uniquely identify the speculative optimization guarded by the uncommon trap
1017 oop _pending_failed_speculation;
1018
1019 // These fields are mutually exclusive in terms of live ranges.
1020 union {
1021 // Communicates the pc at which the most recent implicit exception occurred
1022 // from the signal handler to a deoptimization stub.
1023 address _implicit_exception_pc;
1024
1025 // Communicates an alternative call target to an i2c stub from a JavaCall .
1026 address _alternate_call_target;
1027 } _jvmci;
1028
1029 // Support for high precision, thread sensitive counters in JVMCI compiled code.
1030 jlong* _jvmci_counters;
1031
1032 public:
1033 static jlong* _jvmci_old_thread_counters;
1034 static void collect_counters(typeArrayOop array);
1035 private:
1036 #endif // INCLUDE_JVMCI
1037
1038 StackGuardState _stack_guard_state;
1039
1040 // Precompute the limit of the stack as used in stack overflow checks.
1041 // We load it from here to simplify the stack overflow check in assembly.
1042 address _stack_overflow_limit;
1043 address _reserved_stack_activation;
1044
1045 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1046 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1047 // code)
1048 volatile oop _exception_oop; // Exception thrown in compiled code
1049 volatile address _exception_pc; // PC where exception happened
1050 volatile address _exception_handler_pc; // PC for handler of exception
1051 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
1052
1053 private:
1054 // support for JNI critical regions
1055 jint _jni_active_critical; // count of entries into JNI critical region
1056
1057 // Checked JNI: function name requires exception check
1058 char* _pending_jni_exception_check_fn;
1059
1060 // For deadlock detection.
1061 int _depth_first_number;
1062
1063 // JVMTI PopFrame support
1064 // This is set to popframe_pending to signal that top Java frame should be popped immediately
1065 int _popframe_condition;
1066
1067 // If reallocation of scalar replaced objects fails, we throw OOM
1068 // and during exception propagation, pop the top
1069 // _frames_to_pop_failed_realloc frames, the ones that reference
1070 // failed reallocations.
1071 int _frames_to_pop_failed_realloc;
1072
1073 #ifndef PRODUCT
1074 int _jmp_ring_index;
1075 struct {
1076 // We use intptr_t instead of address so debugger doesn't try and display strings
1077 intptr_t _target;
1078 intptr_t _instruction;
1079 const char* _file;
1080 int _line;
1081 } _jmp_ring[jump_ring_buffer_size];
1082 #endif // PRODUCT
1083
1084 friend class VMThread;
1085 friend class ThreadWaitTransition;
1086 friend class VM_Exit;
1087
1088 void initialize(); // Initialized the instance variables
1089
1090 public:
1091 // Constructor
1092 JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1093 JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1094 ~JavaThread();
1095
1096 #ifdef ASSERT
1097 // verify this JavaThread hasn't be published in the Threads::list yet
1098 void verify_not_published();
1099 #endif
1100
1101 //JNI functiontable getter/setter for JVMTI jni function table interception API.
1102 void set_jni_functions(struct JNINativeInterface_* functionTable) {
1103 _jni_environment.functions = functionTable;
1104 }
1105 struct JNINativeInterface_* get_jni_functions() {
1106 return (struct JNINativeInterface_ *)_jni_environment.functions;
1107 }
1108
1109 // This function is called at thread creation to allow
1110 // platform specific thread variables to be initialized.
1111 void cache_global_variables();
1112
1113 // Executes Shutdown.shutdown()
1114 void invoke_shutdown_hooks();
1115
1116 // Cleanup on thread exit
1117 enum ExitType {
1118 normal_exit,
1119 jni_detach
1120 };
1121 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1122
1123 void cleanup_failed_attach_current_thread();
1124
1125 // Testers
1126 virtual bool is_Java_thread() const { return true; }
1127 virtual bool can_call_java() const { return true; }
1128
1129 // Thread chain operations
1130 JavaThread* next() const { return _next; }
1131 void set_next(JavaThread* p) { _next = p; }
1132
1133 // Thread oop. threadObj() can be NULL for initial JavaThread
1134 // (or for threads attached via JNI)
1135 oop threadObj() const { return _threadObj; }
1136 void set_threadObj(oop p) { _threadObj = p; }
1137
1138 ThreadPriority java_priority() const; // Read from threadObj()
1139
1140 // Prepare thread and add to priority queue. If a priority is
1141 // not specified, use the priority of the thread object. Threads_lock
1142 // must be held while this function is called.
1143 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1144
1145 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
1146 address saved_exception_pc() { return _saved_exception_pc; }
1147
1148
1149 ThreadFunction entry_point() const { return _entry_point; }
1150
1151 // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1152 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1153
1154 // Last frame anchor routines
1155
1156 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
1157
1158 // last_Java_sp
1159 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
1160 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
1161
1162 // last_Java_pc
1163
1164 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
1165
1166 // Safepoint support
1167 #if !(defined(PPC64) || defined(AARCH64))
1168 JavaThreadState thread_state() const { return _thread_state; }
1169 void set_thread_state(JavaThreadState s) { _thread_state = s; }
1170 #else
1171 // Use membars when accessing volatile _thread_state. See
1172 // Threads::create_vm() for size checks.
1173 inline JavaThreadState thread_state() const;
1174 inline void set_thread_state(JavaThreadState s);
1175 #endif
1176 ThreadSafepointState *safepoint_state() const { return _safepoint_state; }
1177 void set_safepoint_state(ThreadSafepointState *state) { _safepoint_state = state; }
1178 bool is_at_poll_safepoint() { return _safepoint_state->is_at_poll_safepoint(); }
1179
1180 // JavaThread termination and lifecycle support:
1181 void smr_delete();
1182 bool on_thread_list() const { return _on_thread_list; }
1183 void set_on_thread_list() { _on_thread_list = true; }
1184
1185 // thread has called JavaThread::exit() or is terminated
1186 bool is_exiting() const;
1187 // thread is terminated (no longer on the threads list); we compare
1188 // against the two non-terminated values so that a freed JavaThread
1189 // will also be considered terminated.
1190 bool check_is_terminated(TerminatedTypes l_terminated) const {
1191 return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1192 }
1193 bool is_terminated() const;
1194 void set_terminated(TerminatedTypes t);
1195 // special for Threads::remove() which is static:
1196 void set_terminated_value();
1197 void block_if_vm_exited();
1198
1199 bool doing_unsafe_access() { return _doing_unsafe_access; }
1200 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
1201
1202 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
1203 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1204
1205 inline void set_polling_page(void* poll_value);
1206 inline volatile void* get_polling_page();
1207
1208 private:
1209 // Support for thread handshake operations
1210 HandshakeState _handshake;
1211 public:
1212 void set_handshake_operation(HandshakeOperation* op) {
1213 _handshake.set_operation(this, op);
1214 }
1215
1216 bool has_handshake() const {
1217 return _handshake.has_operation();
1218 }
1219
1220 void cancel_handshake() {
1221 _handshake.cancel(this);
1222 }
1223
1224 void handshake_process_by_self() {
1225 _handshake.process_by_self(this);
1226 }
1227
1228 void handshake_process_by_vmthread() {
1229 _handshake.process_by_vmthread(this);
1230 }
1231
1232 // Suspend/resume support for JavaThread
1233 private:
1234 inline void set_ext_suspended();
1235 inline void clear_ext_suspended();
1236
1237 public:
1238 void java_suspend();
1239 void java_resume();
1240 int java_suspend_self();
1241
1242 void check_and_wait_while_suspended() {
1243 assert(JavaThread::current() == this, "sanity check");
1244
1245 bool do_self_suspend;
1246 do {
1247 // were we externally suspended while we were waiting?
1248 do_self_suspend = handle_special_suspend_equivalent_condition();
1249 if (do_self_suspend) {
1250 // don't surprise the thread that suspended us by returning
1251 java_suspend_self();
1252 set_suspend_equivalent();
1253 }
1254 } while (do_self_suspend);
1255 }
1256 static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1257 // Check for async exception in addition to safepoint and suspend request.
1258 static void check_special_condition_for_native_trans(JavaThread *thread);
1259
1260 // Same as check_special_condition_for_native_trans but finishes the
1261 // transition into thread_in_Java mode so that it can potentially
1262 // block.
1263 static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1264
1265 bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1266 bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1267 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1268 // Warning: is_ext_suspend_completed() may temporarily drop the
1269 // SR_lock to allow the thread to reach a stable thread state if
1270 // it is currently in a transient thread state.
1271 return is_ext_suspend_completed(false /* !called_by_wait */,
1272 SuspendRetryDelay, bits);
1273 }
1274
1275 // We cannot allow wait_for_ext_suspend_completion() to run forever or
1276 // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1277 // passed as the count and delay parameters. Experiments with specific
1278 // calls to wait_for_ext_suspend_completion() can be done by passing
1279 // other values in the code. Experiments with all calls can be done
1280 // via the appropriate -XX options.
1281 bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1282
1283 // test for suspend - most (all?) of these should go away
1284 bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits);
1285
1286 inline void set_external_suspend();
1287 inline void clear_external_suspend();
1288
1289 inline void set_deopt_suspend();
1290 inline void clear_deopt_suspend();
1291 bool is_deopt_suspend() { return (_suspend_flags & _deopt_suspend) != 0; }
1292
1293 bool is_external_suspend() const {
1294 return (_suspend_flags & _external_suspend) != 0;
1295 }
1296 // Whenever a thread transitions from native to vm/java it must suspend
1297 // if external|deopt suspend is present.
1298 bool is_suspend_after_native() const {
1299 return (_suspend_flags & (_external_suspend | _deopt_suspend)) != 0;
1300 }
1301
1302 // external suspend request is completed
1303 bool is_ext_suspended() const {
1304 return (_suspend_flags & _ext_suspended) != 0;
1305 }
1306
1307 bool is_external_suspend_with_lock() const {
1308 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1309 return is_external_suspend();
1310 }
1311
1312 // Special method to handle a pending external suspend request
1313 // when a suspend equivalent condition lifts.
1314 bool handle_special_suspend_equivalent_condition() {
1315 assert(is_suspend_equivalent(),
1316 "should only be called in a suspend equivalence condition");
1317 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1318 bool ret = is_external_suspend();
1319 if (!ret) {
1320 // not about to self-suspend so clear suspend equivalence
1321 clear_suspend_equivalent();
1322 }
1323 // implied else:
1324 // We have a pending external suspend request so we leave the
1325 // suspend_equivalent flag set until java_suspend_self() sets
1326 // the ext_suspended flag and clears the suspend_equivalent
1327 // flag. This insures that wait_for_ext_suspend_completion()
1328 // will return consistent values.
1329 return ret;
1330 }
1331
1332 // utility methods to see if we are doing some kind of suspension
1333 bool is_being_ext_suspended() const {
1334 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1335 return is_ext_suspended() || is_external_suspend();
1336 }
1337
1338 bool is_suspend_equivalent() const { return _suspend_equivalent; }
1339
1340 void set_suspend_equivalent() { _suspend_equivalent = true; }
1341 void clear_suspend_equivalent() { _suspend_equivalent = false; }
1342
1343 // Thread.stop support
1344 void send_thread_stop(oop throwable);
1345 AsyncRequests clear_special_runtime_exit_condition() {
1346 AsyncRequests x = _special_runtime_exit_condition;
1347 _special_runtime_exit_condition = _no_async_condition;
1348 return x;
1349 }
1350
1351 // Are any async conditions present?
1352 bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1353
1354 void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1355
1356 // these next two are also used for self-suspension and async exception support
1357 void handle_special_runtime_exit_condition(bool check_asyncs = true);
1358
1359 // Return true if JavaThread has an asynchronous condition or
1360 // if external suspension is requested.
1361 bool has_special_runtime_exit_condition() {
1362 // Because we don't use is_external_suspend_with_lock
1363 // it is possible that we won't see an asynchronous external suspend
1364 // request that has just gotten started, i.e., SR_lock grabbed but
1365 // _external_suspend field change either not made yet or not visible
1366 // yet. However, this is okay because the request is asynchronous and
1367 // we will see the new flag value the next time through. It's also
1368 // possible that the external suspend request is dropped after
1369 // we have checked is_external_suspend(), we will recheck its value
1370 // under SR_lock in java_suspend_self().
1371 return (_special_runtime_exit_condition != _no_async_condition) ||
1372 is_external_suspend() || is_trace_suspend();
1373 }
1374
1375 void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; }
1376
1377 inline void set_pending_async_exception(oop e);
1378
1379 // Fast-locking support
1380 bool is_lock_owned(address adr) const;
1381
1382 // Accessors for vframe array top
1383 // The linked list of vframe arrays are sorted on sp. This means when we
1384 // unpack the head must contain the vframe array to unpack.
1385 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1386 vframeArray* vframe_array_head() const { return _vframe_array_head; }
1387
1388 // Side structure for deferring update of java frame locals until deopt occurs
1389 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1390 void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1391
1392 // These only really exist to make debugging deopt problems simpler
1393
1394 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1395 vframeArray* vframe_array_last() const { return _vframe_array_last; }
1396
1397 // The special resourceMark used during deoptimization
1398
1399 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
1400 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
1401
1402 intptr_t* must_deopt_id() { return _must_deopt_id; }
1403 void set_must_deopt_id(intptr_t* id) { _must_deopt_id = id; }
1404 void clear_must_deopt_id() { _must_deopt_id = NULL; }
1405
1406 void set_deopt_compiled_method(CompiledMethod* nm) { _deopt_nmethod = nm; }
1407 CompiledMethod* deopt_compiled_method() { return _deopt_nmethod; }
1408
1409 Method* callee_target() const { return _callee_target; }
1410 void set_callee_target (Method* x) { _callee_target = x; }
1411
1412 // Oop results of vm runtime calls
1413 oop vm_result() const { return _vm_result; }
1414 void set_vm_result (oop x) { _vm_result = x; }
1415
1416 Metadata* vm_result_2() const { return _vm_result_2; }
1417 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
1418
1419 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
1420 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
1421
1422 #if INCLUDE_JVMCI
1423 int pending_deoptimization() const { return _pending_deoptimization; }
1424 oop pending_failed_speculation() const { return _pending_failed_speculation; }
1425 bool adjusting_comp_level() const { return _adjusting_comp_level; }
1426 void set_adjusting_comp_level(bool b) { _adjusting_comp_level = b; }
1427 bool has_pending_monitorenter() const { return _pending_monitorenter; }
1428 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
1429 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
1430 void set_pending_failed_speculation(oop failed_speculation) { _pending_failed_speculation = failed_speculation; }
1431 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1432 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1433 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1434 #endif // INCLUDE_JVMCI
1435
1436 // Exception handling for compiled methods
1437 oop exception_oop() const { return _exception_oop; }
1438 address exception_pc() const { return _exception_pc; }
1439 address exception_handler_pc() const { return _exception_handler_pc; }
1440 bool is_method_handle_return() const { return _is_method_handle_return == 1; }
1441
1442 void set_exception_oop(oop o) { (void)const_cast<oop&>(_exception_oop = o); }
1443 void set_exception_pc(address a) { _exception_pc = a; }
1444 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
1445 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
1446
1447 void clear_exception_oop_and_pc() {
1448 set_exception_oop(NULL);
1449 set_exception_pc(NULL);
1450 }
1451
1452 // Stack overflow support
1453 //
1454 // (small addresses)
1455 //
1456 // -- <-- stack_end() ---
1457 // | |
1458 // | red pages |
1459 // | |
1460 // -- <-- stack_red_zone_base() |
1461 // | |
1462 // | guard
1463 // | yellow pages zone
1464 // | |
1465 // | |
1466 // -- <-- stack_yellow_zone_base() |
1467 // | |
1468 // | |
1469 // | reserved pages |
1470 // | |
1471 // -- <-- stack_reserved_zone_base() --- ---
1472 // /|\ shadow <-- stack_overflow_limit() (somewhere in here)
1473 // | zone
1474 // \|/ size
1475 // some untouched memory ---
1476 //
1477 //
1478 // --
1479 // |
1480 // | shadow zone
1481 // |
1482 // --
1483 // x frame n
1484 // --
1485 // x frame n-1
1486 // x
1487 // --
1488 // ...
1489 //
1490 // --
1491 // x frame 0
1492 // -- <-- stack_base()
1493 //
1494 // (large addresses)
1495 //
1496
1497 private:
1498 // These values are derived from flags StackRedPages, StackYellowPages,
1499 // StackReservedPages and StackShadowPages. The zone size is determined
1500 // ergonomically if page_size > 4K.
1501 static size_t _stack_red_zone_size;
1502 static size_t _stack_yellow_zone_size;
1503 static size_t _stack_reserved_zone_size;
1504 static size_t _stack_shadow_zone_size;
1505 public:
1506 inline size_t stack_available(address cur_sp);
1507
1508 static size_t stack_red_zone_size() {
1509 assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1510 return _stack_red_zone_size;
1511 }
1512 static void set_stack_red_zone_size(size_t s) {
1513 assert(is_aligned(s, os::vm_page_size()),
1514 "We can not protect if the red zone size is not page aligned.");
1515 assert(_stack_red_zone_size == 0, "This should be called only once.");
1516 _stack_red_zone_size = s;
1517 }
1518 address stack_red_zone_base() {
1519 return (address)(stack_end() + stack_red_zone_size());
1520 }
1521 bool in_stack_red_zone(address a) {
1522 return a <= stack_red_zone_base() && a >= stack_end();
1523 }
1524
1525 static size_t stack_yellow_zone_size() {
1526 assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1527 return _stack_yellow_zone_size;
1528 }
1529 static void set_stack_yellow_zone_size(size_t s) {
1530 assert(is_aligned(s, os::vm_page_size()),
1531 "We can not protect if the yellow zone size is not page aligned.");
1532 assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1533 _stack_yellow_zone_size = s;
1534 }
1535
1536 static size_t stack_reserved_zone_size() {
1537 // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1538 return _stack_reserved_zone_size;
1539 }
1540 static void set_stack_reserved_zone_size(size_t s) {
1541 assert(is_aligned(s, os::vm_page_size()),
1542 "We can not protect if the reserved zone size is not page aligned.");
1543 assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1544 _stack_reserved_zone_size = s;
1545 }
1546 address stack_reserved_zone_base() {
1547 return (address)(stack_end() +
1548 (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1549 }
1550 bool in_stack_reserved_zone(address a) {
1551 return (a <= stack_reserved_zone_base()) &&
1552 (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1553 }
1554
1555 static size_t stack_yellow_reserved_zone_size() {
1556 return _stack_yellow_zone_size + _stack_reserved_zone_size;
1557 }
1558 bool in_stack_yellow_reserved_zone(address a) {
1559 return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1560 }
1561
1562 // Size of red + yellow + reserved zones.
1563 static size_t stack_guard_zone_size() {
1564 return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1565 }
1566
1567 static size_t stack_shadow_zone_size() {
1568 assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1569 return _stack_shadow_zone_size;
1570 }
1571 static void set_stack_shadow_zone_size(size_t s) {
1572 // The shadow area is not allocated or protected, so
1573 // it needs not be page aligned.
1574 // But the stack bang currently assumes that it is a
1575 // multiple of page size. This guarantees that the bang
1576 // loop touches all pages in the shadow zone.
1577 // This can be guaranteed differently, as well. E.g., if
1578 // the page size is a multiple of 4K, banging in 4K steps
1579 // suffices to touch all pages. (Some pages are banged
1580 // several times, though.)
1581 assert(is_aligned(s, os::vm_page_size()),
1582 "Stack bang assumes multiple of page size.");
1583 assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1584 _stack_shadow_zone_size = s;
1585 }
1586
1587 void create_stack_guard_pages();
1588 void remove_stack_guard_pages();
1589
1590 void enable_stack_reserved_zone();
1591 void disable_stack_reserved_zone();
1592 void enable_stack_yellow_reserved_zone();
1593 void disable_stack_yellow_reserved_zone();
1594 void enable_stack_red_zone();
1595 void disable_stack_red_zone();
1596
1597 inline bool stack_guard_zone_unused();
1598 inline bool stack_yellow_reserved_zone_disabled();
1599 inline bool stack_reserved_zone_disabled();
1600 inline bool stack_guards_enabled();
1601
1602 address reserved_stack_activation() const { return _reserved_stack_activation; }
1603 void set_reserved_stack_activation(address addr) {
1604 assert(_reserved_stack_activation == stack_base()
1605 || _reserved_stack_activation == NULL
1606 || addr == stack_base(), "Must not be set twice");
1607 _reserved_stack_activation = addr;
1608 }
1609
1610 // Attempt to reguard the stack after a stack overflow may have occurred.
1611 // Returns true if (a) guard pages are not needed on this thread, (b) the
1612 // pages are already guarded, or (c) the pages were successfully reguarded.
1613 // Returns false if there is not enough stack space to reguard the pages, in
1614 // which case the caller should unwind a frame and try again. The argument
1615 // should be the caller's (approximate) sp.
1616 bool reguard_stack(address cur_sp);
1617 // Similar to above but see if current stackpoint is out of the guard area
1618 // and reguard if possible.
1619 bool reguard_stack(void);
1620
1621 address stack_overflow_limit() { return _stack_overflow_limit; }
1622 void set_stack_overflow_limit() {
1623 _stack_overflow_limit =
1624 stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1625 }
1626
1627 // Misc. accessors/mutators
1628 void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; }
1629 void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; }
1630 bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; }
1631
1632 #ifndef PRODUCT
1633 void record_jump(address target, address instr, const char* file, int line);
1634 #endif // PRODUCT
1635
1636 // For assembly stub generation
1637 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
1638 #ifndef PRODUCT
1639 static ByteSize jmp_ring_index_offset() { return byte_offset_of(JavaThread, _jmp_ring_index); }
1640 static ByteSize jmp_ring_offset() { return byte_offset_of(JavaThread, _jmp_ring); }
1641 #endif // PRODUCT
1642 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
1643 static ByteSize pending_jni_exception_check_fn_offset() {
1644 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1645 }
1646 static ByteSize last_Java_sp_offset() {
1647 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1648 }
1649 static ByteSize last_Java_pc_offset() {
1650 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1651 }
1652 static ByteSize frame_anchor_offset() {
1653 return byte_offset_of(JavaThread, _anchor);
1654 }
1655 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
1656 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); }
1657 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); }
1658 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
1659 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
1660 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
1661 #if INCLUDE_JVMCI
1662 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1663 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
1664 static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1665 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1666 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1667 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
1668 #endif // INCLUDE_JVMCI
1669 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
1670 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
1671 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
1672 static ByteSize stack_overflow_limit_offset() { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1673 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1674 static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state); }
1675 static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1676 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
1677
1678 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1679 static ByteSize should_post_on_exceptions_flag_offset() {
1680 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1681 }
1682
1683 // Returns the jni environment for this thread
1684 JNIEnv* jni_environment() { return &_jni_environment; }
1685
1686 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1687 JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1688 // Only return NULL if thread is off the thread list; starting to
1689 // exit should not return NULL.
1690 if (thread_from_jni_env->is_terminated()) {
1691 thread_from_jni_env->block_if_vm_exited();
1692 return NULL;
1693 } else {
1694 return thread_from_jni_env;
1695 }
1696 }
1697
1698 // JNI critical regions. These can nest.
1699 bool in_critical() { return _jni_active_critical > 0; }
1700 bool in_last_critical() { return _jni_active_critical == 1; }
1701 void enter_critical() {
1702 assert(Thread::current() == this ||
1703 (Thread::current()->is_VM_thread() &&
1704 SafepointSynchronize::is_synchronizing()),
1705 "this must be current thread or synchronizing");
1706 _jni_active_critical++;
1707 }
1708 void exit_critical() {
1709 assert(Thread::current() == this, "this must be current thread");
1710 _jni_active_critical--;
1711 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1712 }
1713
1714 // Checked JNI: is the programmer required to check for exceptions, if so specify
1715 // which function name. Returning to a Java frame should implicitly clear the
1716 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1717 // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1718 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1719 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1720 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1721 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1722 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1723
1724 // For deadlock detection
1725 int depth_first_number() { return _depth_first_number; }
1726 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1727
1728 private:
1729 void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1730
1731 public:
1732 MonitorChunk* monitor_chunks() const { return _monitor_chunks; }
1733 void add_monitor_chunk(MonitorChunk* chunk);
1734 void remove_monitor_chunk(MonitorChunk* chunk);
1735 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
1736 void inc_in_deopt_handler() { _in_deopt_handler++; }
1737 void dec_in_deopt_handler() {
1738 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1739 if (_in_deopt_handler > 0) { // robustness
1740 _in_deopt_handler--;
1741 }
1742 }
1743
1744 private:
1745 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1746
1747 public:
1748
1749 // Frame iteration; calls the function f for all frames on the stack
1750 void frames_do(void f(frame*, const RegisterMap*));
1751
1752 // Memory operations
1753 void oops_do(OopClosure* f, CodeBlobClosure* cf);
1754
1755 // Sweeper operations
1756 virtual void nmethods_do(CodeBlobClosure* cf);
1757
1758 // RedefineClasses Support
1759 void metadata_do(void f(Metadata*));
1760
1761 // Misc. operations
1762 char* name() const { return (char*)get_thread_name(); }
1763 void print_on(outputStream* st) const;
1764 void print_value();
1765 void print_thread_state_on(outputStream*) const PRODUCT_RETURN;
1766 void print_thread_state() const PRODUCT_RETURN;
1767 void print_on_error(outputStream* st, char* buf, int buflen) const;
1768 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1769 void verify();
1770 const char* get_thread_name() const;
1771 private:
1772 // factor out low-level mechanics for use in both normal and error cases
1773 const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1774 public:
1775 const char* get_threadgroup_name() const;
1776 const char* get_parent_name() const;
1777
1778 // Accessing frames
1779 frame last_frame() {
1780 _anchor.make_walkable(this);
1781 return pd_last_frame();
1782 }
1783 javaVFrame* last_java_vframe(RegisterMap* reg_map);
1784
1785 // Returns method at 'depth' java or native frames down the stack
1786 // Used for security checks
1787 Klass* security_get_caller_class(int depth);
1788
1789 // Print stack trace in external format
1790 void print_stack_on(outputStream* st);
1791 void print_stack() { print_stack_on(tty); }
1792
1793 // Print stack traces in various internal formats
1794 void trace_stack() PRODUCT_RETURN;
1795 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1796 void trace_frames() PRODUCT_RETURN;
1797 void trace_oops() PRODUCT_RETURN;
1798
1799 // Print an annotated view of the stack frames
1800 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1801 void validate_frame_layout() {
1802 print_frame_layout(0, true);
1803 }
1804
1805 // Returns the number of stack frames on the stack
1806 int depth() const;
1807
1808 // Function for testing deoptimization
1809 void deoptimize();
1810 void make_zombies();
1811
1812 void deoptimized_wrt_marked_nmethods();
1813
1814 public:
1815 // Returns the running thread as a JavaThread
1816 static inline JavaThread* current();
1817
1818 // Returns the active Java thread. Do not use this if you know you are calling
1819 // from a JavaThread, as it's slower than JavaThread::current. If called from
1820 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1821 // operation. You may not want that either.
1822 static JavaThread* active();
1823
1824 inline CompilerThread* as_CompilerThread();
1825
1826 public:
1827 virtual void run();
1828 void thread_main_inner();
1829
1830 private:
1831 // PRIVILEGED STACK
1832 PrivilegedElement* _privileged_stack_top;
1833 GrowableArray<oop>* _array_for_gc;
1834 public:
1835
1836 // Returns the privileged_stack information.
1837 PrivilegedElement* privileged_stack_top() const { return _privileged_stack_top; }
1838 void set_privileged_stack_top(PrivilegedElement *e) { _privileged_stack_top = e; }
1839 void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1840
1841 public:
1842 // Thread local information maintained by JVMTI.
1843 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1844 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1845 // getter is used to get this JavaThread's JvmtiThreadState if it has
1846 // one which means NULL can be returned. JvmtiThreadState::state_for()
1847 // is used to get the specified JavaThread's JvmtiThreadState if it has
1848 // one or it allocates a new JvmtiThreadState for the JavaThread and
1849 // returns it. JvmtiThreadState::state_for() will return NULL only if
1850 // the specified JavaThread is exiting.
1851 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1852 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1853 void set_jvmti_get_loaded_classes_closure(JvmtiGetLoadedClassesClosure* value) { _jvmti_get_loaded_classes_closure = value; }
1854 JvmtiGetLoadedClassesClosure* get_jvmti_get_loaded_classes_closure() const { return _jvmti_get_loaded_classes_closure; }
1855
1856 // JVMTI PopFrame support
1857 // Setting and clearing popframe_condition
1858 // All of these enumerated values are bits. popframe_pending
1859 // indicates that a PopFrame() has been requested and not yet been
1860 // completed. popframe_processing indicates that that PopFrame() is in
1861 // the process of being completed. popframe_force_deopt_reexecution_bit
1862 // indicates that special handling is required when returning to a
1863 // deoptimized caller.
1864 enum PopCondition {
1865 popframe_inactive = 0x00,
1866 popframe_pending_bit = 0x01,
1867 popframe_processing_bit = 0x02,
1868 popframe_force_deopt_reexecution_bit = 0x04
1869 };
1870 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1871 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1872 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1873 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1874 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1875 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1876 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1877 void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1878 #ifdef CC_INTERP
1879 bool pop_frame_pending(void) { return ((_popframe_condition & popframe_pending_bit) != 0); }
1880 void clr_pop_frame_pending(void) { _popframe_condition = popframe_inactive; }
1881 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1882 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
1883 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
1884 #endif
1885
1886 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
1887 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
1888 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
1889
1890 private:
1891 // Saved incoming arguments to popped frame.
1892 // Used only when popped interpreted frame returns to deoptimized frame.
1893 void* _popframe_preserved_args;
1894 int _popframe_preserved_args_size;
1895
1896 public:
1897 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
1898 void* popframe_preserved_args();
1899 ByteSize popframe_preserved_args_size();
1900 WordSize popframe_preserved_args_size_in_words();
1901 void popframe_free_preserved_args();
1902
1903
1904 private:
1905 JvmtiThreadState *_jvmti_thread_state;
1906 JvmtiGetLoadedClassesClosure* _jvmti_get_loaded_classes_closure;
1907
1908 // Used by the interpreter in fullspeed mode for frame pop, method
1909 // entry, method exit and single stepping support. This field is
1910 // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
1911 // It can be set to zero asynchronously (i.e., without a VM operation
1912 // or a lock) so we have to be very careful.
1913 int _interp_only_mode;
1914
1915 public:
1916 // used by the interpreter for fullspeed debugging support (see above)
1917 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1918 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
1919 int get_interp_only_mode() { return _interp_only_mode; }
1920 void increment_interp_only_mode() { ++_interp_only_mode; }
1921 void decrement_interp_only_mode() { --_interp_only_mode; }
1922
1923 // support for cached flag that indicates whether exceptions need to be posted for this thread
1924 // if this is false, we can avoid deoptimizing when events are thrown
1925 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1926 private:
1927 int _should_post_on_exceptions_flag;
1928
1929 public:
1930 int should_post_on_exceptions_flag() { return _should_post_on_exceptions_flag; }
1931 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
1932
1933 private:
1934 ThreadStatistics *_thread_stat;
1935
1936 public:
1937 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
1938
1939 // Return a blocker object for which this thread is blocked parking.
1940 oop current_park_blocker();
1941
1942 private:
1943 static size_t _stack_size_at_create;
1944
1945 public:
1946 static inline size_t stack_size_at_create(void) {
1947 return _stack_size_at_create;
1948 }
1949 static inline void set_stack_size_at_create(size_t value) {
1950 _stack_size_at_create = value;
1951 }
1952
1953 // Machine dependent stuff
1954 #include OS_CPU_HEADER(thread)
1955
1956 public:
1957 void set_blocked_on_compilation(bool value) {
1958 _blocked_on_compilation = value;
1959 }
1960
1961 bool blocked_on_compilation() {
1962 return _blocked_on_compilation;
1963 }
1964 protected:
1965 bool _blocked_on_compilation;
1966
1967
1968 // JSR166 per-thread parker
1969 private:
1970 Parker* _parker;
1971 public:
1972 Parker* parker() { return _parker; }
1973
1974 // Biased locking support
1975 private:
1976 GrowableArray<MonitorInfo*>* _cached_monitor_info;
1977 public:
1978 GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
1979 void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
1980
1981 // clearing/querying jni attach status
1982 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
1983 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
1984 inline void set_done_attaching_via_jni();
1985 };
1986
1987 // Inline implementation of JavaThread::current
1988 inline JavaThread* JavaThread::current() {
1989 Thread* thread = Thread::current();
1990 assert(thread->is_Java_thread(), "just checking");
1991 return (JavaThread*)thread;
1992 }
1993
1994 inline CompilerThread* JavaThread::as_CompilerThread() {
1995 assert(is_Compiler_thread(), "just checking");
1996 return (CompilerThread*)this;
1997 }
1998
1999 // Dedicated thread to sweep the code cache
2000 class CodeCacheSweeperThread : public JavaThread {
2001 CompiledMethod* _scanned_compiled_method; // nmethod being scanned by the sweeper
2002 public:
2003 CodeCacheSweeperThread();
2004 // Track the nmethod currently being scanned by the sweeper
2005 void set_scanned_compiled_method(CompiledMethod* cm) {
2006 assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value");
2007 _scanned_compiled_method = cm;
2008 }
2009
2010 // Hide sweeper thread from external view.
2011 bool is_hidden_from_external_view() const { return true; }
2012
2013 bool is_Code_cache_sweeper_thread() const { return true; }
2014
2015 // Prevent GC from unloading _scanned_compiled_method
2016 void oops_do(OopClosure* f, CodeBlobClosure* cf);
2017 void nmethods_do(CodeBlobClosure* cf);
2018 };
2019
2020 // A thread used for Compilation.
2021 class CompilerThread : public JavaThread {
2022 friend class VMStructs;
2023 private:
2024 CompilerCounters* _counters;
2025
2026 ciEnv* _env;
2027 CompileLog* _log;
2028 CompileTask* volatile _task; // print_threads_compiling can read this concurrently.
2029 CompileQueue* _queue;
2030 BufferBlob* _buffer_blob;
2031
2032 AbstractCompiler* _compiler;
2033 TimeStamp _idle_time;
2034
2035 public:
2036
2037 static CompilerThread* current();
2038
2039 CompilerThread(CompileQueue* queue, CompilerCounters* counters);
2040 ~CompilerThread();
2041
2042 bool is_Compiler_thread() const { return true; }
2043
2044 virtual bool can_call_java() const;
2045
2046 // Hide native compiler threads from external view.
2047 bool is_hidden_from_external_view() const { return !can_call_java(); }
2048
2049 void set_compiler(AbstractCompiler* c) { _compiler = c; }
2050 AbstractCompiler* compiler() const { return _compiler; }
2051
2052 CompileQueue* queue() const { return _queue; }
2053 CompilerCounters* counters() const { return _counters; }
2054
2055 // Get/set the thread's compilation environment.
2056 ciEnv* env() { return _env; }
2057 void set_env(ciEnv* env) { _env = env; }
2058
2059 BufferBlob* get_buffer_blob() const { return _buffer_blob; }
2060 void set_buffer_blob(BufferBlob* b) { _buffer_blob = b; }
2061
2062 // Get/set the thread's logging information
2063 CompileLog* log() { return _log; }
2064 void init_log(CompileLog* log) {
2065 // Set once, for good.
2066 assert(_log == NULL, "set only once");
2067 _log = log;
2068 }
2069
2070 void start_idle_timer() { _idle_time.update(); }
2071 jlong idle_time_millis() {
2072 return TimeHelper::counter_to_millis(_idle_time.ticks_since_update());
2073 }
2074
2075 #ifndef PRODUCT
2076 private:
2077 IdealGraphPrinter *_ideal_graph_printer;
2078 public:
2079 IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; }
2080 void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2081 #endif
2082
2083 // Get/set the thread's current task
2084 CompileTask* task() { return _task; }
2085 void set_task(CompileTask* task) { _task = task; }
2086 };
2087
2088 inline CompilerThread* CompilerThread::current() {
2089 return JavaThread::current()->as_CompilerThread();
2090 }
2091
2092 // The active thread queue. It also keeps track of the current used
2093 // thread priorities.
2094 class Threads: AllStatic {
2095 friend class VMStructs;
2096 private:
2097 static JavaThread* _thread_list;
2098 static int _number_of_threads;
2099 static int _number_of_non_daemon_threads;
2100 static int _return_code;
2101 static int _thread_claim_parity;
2102 #ifdef ASSERT
2103 static bool _vm_complete;
2104 #endif
2105
2106 static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2107 static void initialize_jsr292_core_classes(TRAPS);
2108
2109 public:
2110 // Thread management
2111 // force_daemon is a concession to JNI, where we may need to add a
2112 // thread to the thread list before allocating its thread object
2113 static void add(JavaThread* p, bool force_daemon = false);
2114 static void remove(JavaThread* p);
2115 static void non_java_threads_do(ThreadClosure* tc);
2116 static void threads_do(ThreadClosure* tc);
2117 static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
2118
2119 // Initializes the vm and creates the vm thread
2120 static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
2121 static void convert_vm_init_libraries_to_agents();
2122 static void create_vm_init_libraries();
2123 static void create_vm_init_agents();
2124 static void shutdown_vm_agents();
2125 static bool destroy_vm();
2126 // Supported VM versions via JNI
2127 // Includes JNI_VERSION_1_1
2128 static jboolean is_supported_jni_version_including_1_1(jint version);
2129 // Does not include JNI_VERSION_1_1
2130 static jboolean is_supported_jni_version(jint version);
2131
2132 // The "thread claim parity" provides a way for threads to be claimed
2133 // by parallel worker tasks.
2134 //
2135 // Each thread contains a a "parity" field. A task will claim the
2136 // thread only if its parity field is the same as the global parity,
2137 // which is updated by calling change_thread_claim_parity().
2138 //
2139 // For this to work change_thread_claim_parity() needs to be called
2140 // exactly once in sequential code before starting parallel tasks
2141 // that should claim threads.
2142 //
2143 // New threads get their parity set to 0 and change_thread_claim_parity()
2144 // never set the global parity to 0.
2145 static int thread_claim_parity() { return _thread_claim_parity; }
2146 static void change_thread_claim_parity();
2147 static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
2148
2149 // Apply "f->do_oop" to all root oops in all threads.
2150 // This version may only be called by sequential code.
2151 static void oops_do(OopClosure* f, CodeBlobClosure* cf);
2152 // This version may be called by sequential or parallel code.
2153 static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
2154 // This creates a list of GCTasks, one per thread.
2155 static void create_thread_roots_tasks(GCTaskQueue* q);
2156 // This creates a list of GCTasks, one per thread, for marking objects.
2157 static void create_thread_roots_marking_tasks(GCTaskQueue* q);
2158
2159 // Apply "f->do_oop" to roots in all threads that
2160 // are part of compiled frames
2161 static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf);
2162
2163 static void convert_hcode_pointers();
2164 static void restore_hcode_pointers();
2165
2166 // Sweeper
2167 static void nmethods_do(CodeBlobClosure* cf);
2168
2169 // RedefineClasses support
2170 static void metadata_do(void f(Metadata*));
2171 static void metadata_handles_do(void f(Metadata*));
2172
2173 #ifdef ASSERT
2174 static bool is_vm_complete() { return _vm_complete; }
2175 #endif
2176
2177 // Verification
2178 static void verify();
2179 static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks);
2180 static void print(bool print_stacks, bool internal_format) {
2181 // this function is only used by debug.cpp
2182 print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */);
2183 }
2184 static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2185 static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
2186 int buflen, bool* found_current);
2187 static void print_threads_compiling(outputStream* st, char* buf, int buflen);
2188
2189 // Get Java threads that are waiting to enter a monitor.
2190 static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
2191 int count, address monitor);
2192
2193 // Get owning Java thread from the monitor's owner field.
2194 static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
2195 address owner);
2196
2197 // Number of threads on the active threads list
2198 static int number_of_threads() { return _number_of_threads; }
2199 // Number of non-daemon threads on the active threads list
2200 static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; }
2201
2202 // Deoptimizes all frames tied to marked nmethods
2203 static void deoptimized_wrt_marked_nmethods();
2204 };
2205
2206
2207 // Thread iterator
2208 class ThreadClosure: public StackObj {
2209 public:
2210 virtual void do_thread(Thread* thread) = 0;
2211 };
2212
2213 class SignalHandlerMark: public StackObj {
2214 private:
2215 Thread* _thread;
2216 public:
2217 SignalHandlerMark(Thread* t) {
2218 _thread = t;
2219 if (_thread) _thread->enter_signal_handler();
2220 }
2221 ~SignalHandlerMark() {
2222 if (_thread) _thread->leave_signal_handler();
2223 _thread = NULL;
2224 }
2225 };
2226
2227
2228 #endif // SHARE_VM_RUNTIME_THREAD_HPP