1 /*
2 * Copyright (c) 1997, 2020, 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_RUNTIME_THREAD_HPP
26 #define SHARE_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/stubRoutines.hpp"
44 #include "runtime/threadHeapSampler.hpp"
45 #include "runtime/threadLocalStorage.hpp"
46 #include "runtime/threadStatisticalInfo.hpp"
47 #include "runtime/unhandledOops.hpp"
48 #include "utilities/align.hpp"
49 #include "utilities/exceptions.hpp"
50 #include "utilities/globalDefinitions.hpp"
51 #include "utilities/macros.hpp"
52 #if INCLUDE_JFR
53 #include "jfr/support/jfrThreadExtension.hpp"
54 #endif
55
56
57 class SafeThreadsListPtr;
58 class ThreadSafepointState;
59 class ThreadsList;
60 class ThreadsSMRSupport;
61
62 class JvmtiRawMonitor;
63 class JvmtiThreadState;
64 class ThreadStatistics;
65 class ConcurrentLocksDump;
66 class ParkEvent;
67 class Parker;
68 class MonitorInfo;
69
70 class AbstractCompiler;
71 class ciEnv;
72 class CompileThread;
73 class CompileLog;
74 class CompileTask;
75 class CompileQueue;
76 class CompilerCounters;
77
78 class vframeArray;
79 class vframe;
80 class javaVFrame;
81
82 class DeoptResourceMark;
83 class jvmtiDeferredLocalVariableSet;
84
85 class ThreadClosure;
86 class ICRefillVerifier;
87 class IdealGraphPrinter;
88
89 class JVMCIEnv;
90 class JVMCIPrimitiveArray;
91
92 class Metadata;
93 class ResourceArea;
94
95 DEBUG_ONLY(class ResourceMark;)
96
97 class WorkerThread;
98
99 // Class hierarchy
100 // - Thread
101 // - JavaThread
102 // - various subclasses eg CompilerThread, ServiceThread
103 // - NonJavaThread
104 // - NamedThread
105 // - VMThread
106 // - ConcurrentGCThread
107 // - WorkerThread
108 // - GangWorker
109 // - WatcherThread
110 // - JfrThreadSampler
111 //
112 // All Thread subclasses must be either JavaThread or NonJavaThread.
113 // This means !t->is_Java_thread() iff t is a NonJavaThread, or t is
114 // a partially constructed/destroyed Thread.
115
116 // Thread execution sequence and actions:
117 // All threads:
118 // - thread_native_entry // per-OS native entry point
119 // - stack initialization
120 // - other OS-level initialization (signal masks etc)
121 // - handshake with creating thread (if not started suspended)
122 // - this->call_run() // common shared entry point
123 // - shared common initialization
124 // - this->pre_run() // virtual per-thread-type initialization
125 // - this->run() // virtual per-thread-type "main" logic
126 // - shared common tear-down
127 // - this->post_run() // virtual per-thread-type tear-down
128 // - // 'this' no longer referenceable
129 // - OS-level tear-down (minimal)
130 // - final logging
131 //
132 // For JavaThread:
133 // - this->run() // virtual but not normally overridden
134 // - this->thread_main_inner() // extra call level to ensure correct stack calculations
135 // - this->entry_point() // set differently for each kind of JavaThread
136
137 class Thread: public ThreadShadow {
138 friend class VMStructs;
139 friend class JVMCIVMStructs;
140 private:
141
142 #ifndef USE_LIBRARY_BASED_TLS_ONLY
143 // Current thread is maintained as a thread-local variable
144 static THREAD_LOCAL Thread* _thr_current;
145 #endif
146
147 // Thread local data area available to the GC. The internal
148 // structure and contents of this data area is GC-specific.
149 // Only GC and GC barrier code should access this data area.
150 GCThreadLocalData _gc_data;
151
152 public:
153 static ByteSize gc_data_offset() {
154 return byte_offset_of(Thread, _gc_data);
155 }
156
157 template <typename T> T* gc_data() {
158 STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data));
159 return reinterpret_cast<T*>(&_gc_data);
160 }
161
162 // Exception handling
163 // (Note: _pending_exception and friends are in ThreadShadow)
164 //oop _pending_exception; // pending exception for current thread
165 // const char* _exception_file; // file information for exception (debugging only)
166 // int _exception_line; // line information for exception (debugging only)
167 protected:
168
169 DEBUG_ONLY(static Thread* _starting_thread;)
170
171 // Support for forcing alignment of thread objects for biased locking
172 void* _real_malloc_address;
173
174 // JavaThread lifecycle support:
175 friend class SafeThreadsListPtr; // for _threads_list_ptr, cmpxchg_threads_hazard_ptr(), {dec_,inc_,}nested_threads_hazard_ptr_cnt(), {g,s}et_threads_hazard_ptr(), inc_nested_handle_cnt(), tag_hazard_ptr() access
176 friend class ScanHazardPtrGatherProtectedThreadsClosure; // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
177 friend class ScanHazardPtrGatherThreadsListClosure; // for get_threads_hazard_ptr(), untag_hazard_ptr() access
178 friend class ScanHazardPtrPrintMatchingThreadsClosure; // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
179 friend class ThreadsSMRSupport; // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
180
181 ThreadsList* volatile _threads_hazard_ptr;
182 SafeThreadsListPtr* _threads_list_ptr;
183 ThreadsList* cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
184 ThreadsList* get_threads_hazard_ptr();
185 void set_threads_hazard_ptr(ThreadsList* new_list);
186 static bool is_hazard_ptr_tagged(ThreadsList* list) {
187 return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
188 }
189 static ThreadsList* tag_hazard_ptr(ThreadsList* list) {
190 return (ThreadsList*)(intptr_t(list) | intptr_t(1));
191 }
192 static ThreadsList* untag_hazard_ptr(ThreadsList* list) {
193 return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
194 }
195 // This field is enabled via -XX:+EnableThreadSMRStatistics:
196 uint _nested_threads_hazard_ptr_cnt;
197 void dec_nested_threads_hazard_ptr_cnt() {
198 assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
199 _nested_threads_hazard_ptr_cnt--;
200 }
201 void inc_nested_threads_hazard_ptr_cnt() {
202 _nested_threads_hazard_ptr_cnt++;
203 }
204 uint nested_threads_hazard_ptr_cnt() {
205 return _nested_threads_hazard_ptr_cnt;
206 }
207
208 public:
209 void* operator new(size_t size) throw() { return allocate(size, true); }
210 void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
211 return allocate(size, false); }
212 void operator delete(void* p);
213
214 protected:
215 static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
216 private:
217
218 // ***************************************************************
219 // Suspend and resume support
220 // ***************************************************************
221 //
222 // VM suspend/resume no longer exists - it was once used for various
223 // things including safepoints but was deprecated and finally removed
224 // in Java 7. Because VM suspension was considered "internal" Java-level
225 // suspension was considered "external", and this legacy naming scheme
226 // remains.
227 //
228 // External suspend/resume requests come from JVM_SuspendThread,
229 // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
230 // ResumeThread. External
231 // suspend requests cause _external_suspend to be set and external
232 // resume requests cause _external_suspend to be cleared.
233 // External suspend requests do not nest on top of other external
234 // suspend requests. The higher level APIs reject suspend requests
235 // for already suspended threads.
236 //
237 // The external_suspend
238 // flag is checked by has_special_runtime_exit_condition() and java thread
239 // will self-suspend when handle_special_runtime_exit_condition() is
240 // called. Most uses of the _thread_blocked state in JavaThreads are
241 // considered the same as being externally suspended; if the blocking
242 // condition lifts, the JavaThread will self-suspend. Other places
243 // where VM checks for external_suspend include:
244 // + mutex granting (do not enter monitors when thread is suspended)
245 // + state transitions from _thread_in_native
246 //
247 // In general, java_suspend() does not wait for an external suspend
248 // request to complete. When it returns, the only guarantee is that
249 // the _external_suspend field is true.
250 //
251 // wait_for_ext_suspend_completion() is used to wait for an external
252 // suspend request to complete. External suspend requests are usually
253 // followed by some other interface call that requires the thread to
254 // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
255 // the interface that requires quiescence, we give the JavaThread a
256 // chance to self-suspend before we need it to be quiescent. This
257 // improves overall suspend/query performance.
258 //
259 // _suspend_flags controls the behavior of java_ suspend/resume.
260 // It must be set under the protection of SR_lock. Read from the flag is
261 // OK without SR_lock as long as the value is only used as a hint.
262 // (e.g., check _external_suspend first without lock and then recheck
263 // inside SR_lock and finish the suspension)
264 //
265 // _suspend_flags is also overloaded for other "special conditions" so
266 // that a single check indicates whether any special action is needed
267 // eg. for async exceptions.
268 // -------------------------------------------------------------------
269 // Notes:
270 // 1. The suspend/resume logic no longer uses ThreadState in OSThread
271 // but we still update its value to keep other part of the system (mainly
272 // JVMTI) happy. ThreadState is legacy code (see notes in
273 // osThread.hpp).
274 //
275 // 2. It would be more natural if set_external_suspend() is private and
276 // part of java_suspend(), but that probably would affect the suspend/query
277 // performance. Need more investigation on this.
278
279 // suspend/resume lock: used for self-suspend
280 Monitor* _SR_lock;
281
282 protected:
283 enum SuspendFlags {
284 // NOTE: avoid using the sign-bit as cc generates different test code
285 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
286
287 _external_suspend = 0x20000000U, // thread is asked to self suspend
288 _ext_suspended = 0x40000000U, // thread has self-suspended
289
290 _has_async_exception = 0x00000001U, // there is a pending async exception
291 _critical_native_unlock = 0x00000002U, // Must call back to unlock JNI critical lock
292
293 _trace_flag = 0x00000004U // call tracing backend
294 };
295
296 // various suspension related flags - atomically updated
297 // overloaded for async exception checking in check_special_condition_for_native_trans.
298 volatile uint32_t _suspend_flags;
299
300 private:
301 int _num_nested_signal;
302
303 DEBUG_ONLY(bool _suspendible_thread;)
304
305 public:
306 void enter_signal_handler() { _num_nested_signal++; }
307 void leave_signal_handler() { _num_nested_signal--; }
308 bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
309
310 // Determines if a heap allocation failure will be retried
311 // (e.g., by deoptimizing and re-executing in the interpreter).
312 // In this case, the failed allocation must raise
313 // Universe::out_of_memory_error_retry() and omit side effects
314 // such as JVMTI events and handling -XX:+HeapDumpOnOutOfMemoryError
315 // and -XX:OnOutOfMemoryError.
316 virtual bool in_retryable_allocation() const { return false; }
317
318 #ifdef ASSERT
319 void set_suspendible_thread() {
320 _suspendible_thread = true;
321 }
322
323 void clear_suspendible_thread() {
324 _suspendible_thread = false;
325 }
326
327 bool is_suspendible_thread() { return _suspendible_thread; }
328 #endif
329
330 private:
331 // Active_handles points to a block of handles
332 JNIHandleBlock* _active_handles;
333
334 // One-element thread local free list
335 JNIHandleBlock* _free_handle_block;
336
337 // Point to the last handle mark
338 HandleMark* _last_handle_mark;
339
340 // Claim value for parallel iteration over threads.
341 uintx _threads_do_token;
342
343 // Support for GlobalCounter
344 private:
345 volatile uintx _rcu_counter;
346 public:
347 volatile uintx* get_rcu_counter() {
348 return &_rcu_counter;
349 }
350
351 public:
352 void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; }
353 HandleMark* last_handle_mark() const { return _last_handle_mark; }
354 private:
355
356 #ifdef ASSERT
357 ICRefillVerifier* _missed_ic_stub_refill_verifier;
358
359 public:
360 ICRefillVerifier* missed_ic_stub_refill_verifier() {
361 return _missed_ic_stub_refill_verifier;
362 }
363
364 void set_missed_ic_stub_refill_verifier(ICRefillVerifier* verifier) {
365 _missed_ic_stub_refill_verifier = verifier;
366 }
367 #endif // ASSERT
368
369 private:
370
371 // Debug support for checking if code allows safepoints or not.
372 // Safepoints in the VM can happen because of allocation, invoking a VM operation, or blocking on
373 // mutex, or blocking on an object synchronizer (Java locking).
374 // If _no_safepoint_count is non-zero, then an assertion failure will happen in any of
375 // the above cases.
376 //
377 // The class NoSafepointVerifier is used to set this counter.
378 //
379 NOT_PRODUCT(int _no_safepoint_count;) // If 0, thread allow a safepoint to happen
380
381 private:
382 // Used by SkipGCALot class.
383 NOT_PRODUCT(bool _skip_gcalot;) // Should we elide gc-a-lot?
384
385 friend class GCLocker;
386 friend class NoSafepointVerifier;
387 friend class PauseNoSafepointVerifier;
388
389 volatile void* _polling_page; // Thread local polling page
390
391 ThreadLocalAllocBuffer _tlab; // Thread-local eden
392 jlong _allocated_bytes; // Cumulative number of bytes allocated on
393 // the Java heap
394 ThreadHeapSampler _heap_sampler; // For use when sampling the memory.
395
396 ThreadStatisticalInfo _statistical_info; // Statistics about the thread
397
398 JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;) // Thread-local data for jfr
399
400 int _vm_operation_started_count; // VM_Operation support
401 int _vm_operation_completed_count; // VM_Operation support
402
403 ObjectMonitor* _current_pending_monitor; // ObjectMonitor this thread
404 // is waiting to lock
405 bool _current_pending_monitor_is_from_java; // locking is from Java code
406 JvmtiRawMonitor* _current_pending_raw_monitor; // JvmtiRawMonitor this thread
407 // is waiting to lock
408
409
410 // ObjectMonitor on which this thread called Object.wait()
411 ObjectMonitor* _current_waiting_monitor;
412
413 // Per-thread ObjectMonitor lists:
414 public:
415 ObjectMonitor* om_free_list; // SLL of free ObjectMonitors
416 int om_free_count; // # on om_free_list
417 int om_free_provision; // # to try to allocate next
418 ObjectMonitor* om_in_use_list; // SLL of in-use ObjectMonitors
419 int om_in_use_count; // # on om_in_use_list
420
421 #ifdef ASSERT
422 private:
423 volatile uint64_t _visited_for_critical_count;
424
425 public:
426 void set_visited_for_critical_count(uint64_t safepoint_id) {
427 assert(_visited_for_critical_count == 0, "Must be reset before set");
428 assert((safepoint_id & 0x1) == 1, "Must be odd");
429 _visited_for_critical_count = safepoint_id;
430 }
431 void reset_visited_for_critical_count(uint64_t safepoint_id) {
432 assert(_visited_for_critical_count == safepoint_id, "Was not visited");
433 _visited_for_critical_count = 0;
434 }
435 bool was_visited_for_critical_count(uint64_t safepoint_id) const {
436 return _visited_for_critical_count == safepoint_id;
437 }
438 #endif
439
440 public:
441 enum {
442 is_definitely_current_thread = true
443 };
444
445 public:
446 // Constructor
447 Thread();
448 virtual ~Thread() = 0; // Thread is abstract.
449
450 // Manage Thread::current()
451 void initialize_thread_current();
452 static void clear_thread_current(); // TLS cleanup needed before threads terminate
453
454 protected:
455 // To be implemented by children.
456 virtual void run() = 0;
457 virtual void pre_run() = 0;
458 virtual void post_run() = 0; // Note: Thread must not be deleted prior to calling this!
459
460 #ifdef ASSERT
461 enum RunState {
462 PRE_CALL_RUN,
463 CALL_RUN,
464 PRE_RUN,
465 RUN,
466 POST_RUN
467 // POST_CALL_RUN - can't define this one as 'this' may be deleted when we want to set it
468 };
469 RunState _run_state; // for lifecycle checks
470 #endif
471
472
473 public:
474 // invokes <ChildThreadClass>::run(), with common preparations and cleanups.
475 void call_run();
476
477 // Testers
478 virtual bool is_VM_thread() const { return false; }
479 virtual bool is_Java_thread() const { return false; }
480 virtual bool is_Compiler_thread() const { return false; }
481 virtual bool is_Code_cache_sweeper_thread() const { return false; }
482 virtual bool is_service_thread() const { return false; }
483 virtual bool is_hidden_from_external_view() const { return false; }
484 virtual bool is_jvmti_agent_thread() const { return false; }
485 // True iff the thread can perform GC operations at a safepoint.
486 // Generally will be true only of VM thread and parallel GC WorkGang
487 // threads.
488 virtual bool is_GC_task_thread() const { return false; }
489 virtual bool is_Watcher_thread() const { return false; }
490 virtual bool is_ConcurrentGC_thread() const { return false; }
491 virtual bool is_Named_thread() const { return false; }
492 virtual bool is_Worker_thread() const { return false; }
493
494 // Can this thread make Java upcalls
495 virtual bool can_call_java() const { return false; }
496
497 // Is this a JavaThread that is on the VM's current ThreadsList?
498 // If so it must participate in the safepoint protocol.
499 virtual bool is_active_Java_thread() const { return false; }
500
501 // Casts
502 virtual WorkerThread* as_Worker_thread() const { return NULL; }
503
504 virtual char* name() const { return (char*)"Unknown thread"; }
505
506 // Returns the current thread (ASSERTS if NULL)
507 static inline Thread* current();
508 // Returns the current thread, or NULL if not attached
509 static inline Thread* current_or_null();
510 // Returns the current thread, or NULL if not attached, and is
511 // safe for use from signal-handlers
512 static inline Thread* current_or_null_safe();
513
514 // Common thread operations
515 #ifdef ASSERT
516 static void check_for_dangling_thread_pointer(Thread *thread);
517 #endif
518 static void set_priority(Thread* thread, ThreadPriority priority);
519 static ThreadPriority get_priority(const Thread* const thread);
520 static void start(Thread* thread);
521
522 void set_native_thread_name(const char *name) {
523 assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
524 os::set_native_thread_name(name);
525 }
526
527 Monitor* SR_lock() const { return _SR_lock; }
528
529 bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
530
531 inline void set_suspend_flag(SuspendFlags f);
532 inline void clear_suspend_flag(SuspendFlags f);
533
534 inline void set_has_async_exception();
535 inline void clear_has_async_exception();
536
537 bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
538
539 inline void set_critical_native_unlock();
540 inline void clear_critical_native_unlock();
541
542 inline void set_trace_flag();
543 inline void clear_trace_flag();
544
545 // Support for Unhandled Oop detection
546 // Add the field for both, fastdebug and debug, builds to keep
547 // Thread's fields layout the same.
548 // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
549 #ifdef CHECK_UNHANDLED_OOPS
550 private:
551 UnhandledOops* _unhandled_oops;
552 #elif defined(ASSERT)
553 private:
554 void* _unhandled_oops;
555 #endif
556 #ifdef CHECK_UNHANDLED_OOPS
557 public:
558 UnhandledOops* unhandled_oops() { return _unhandled_oops; }
559 // Mark oop safe for gc. It may be stack allocated but won't move.
560 void allow_unhandled_oop(oop *op) {
561 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
562 }
563 // Clear oops at safepoint so crashes point to unhandled oop violator
564 void clear_unhandled_oops() {
565 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
566 }
567 #endif // CHECK_UNHANDLED_OOPS
568
569 public:
570 #ifndef PRODUCT
571 bool skip_gcalot() { return _skip_gcalot; }
572 void set_skip_gcalot(bool v) { _skip_gcalot = v; }
573 #endif
574
575 // Installs a pending exception to be inserted later
576 static void send_async_exception(oop thread_oop, oop java_throwable);
577
578 // Resource area
579 ResourceArea* resource_area() const { return _resource_area; }
580 void set_resource_area(ResourceArea* area) { _resource_area = area; }
581
582 OSThread* osthread() const { return _osthread; }
583 void set_osthread(OSThread* thread) { _osthread = thread; }
584
585 // JNI handle support
586 JNIHandleBlock* active_handles() const { return _active_handles; }
587 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
588 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
589 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
590
591 // Internal handle support
592 HandleArea* handle_area() const { return _handle_area; }
593 void set_handle_area(HandleArea* area) { _handle_area = area; }
594
595 GrowableArray<Metadata*>* metadata_handles() const { return _metadata_handles; }
596 void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
597
598 // Thread-Local Allocation Buffer (TLAB) support
599 ThreadLocalAllocBuffer& tlab() { return _tlab; }
600 void initialize_tlab() {
601 if (UseTLAB) {
602 tlab().initialize();
603 }
604 }
605
606 jlong allocated_bytes() { return _allocated_bytes; }
607 void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
608 void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
609 inline jlong cooked_allocated_bytes();
610
611 ThreadHeapSampler& heap_sampler() { return _heap_sampler; }
612
613 ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
614
615 JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
616
617 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; }
618
619 // VM operation support
620 int vm_operation_ticket() { return ++_vm_operation_started_count; }
621 int vm_operation_completed_count() { return _vm_operation_completed_count; }
622 void increment_vm_operation_completed_count() { _vm_operation_completed_count++; }
623
624 // For tracking the heavyweight monitor the thread is pending on.
625 ObjectMonitor* current_pending_monitor() {
626 return _current_pending_monitor;
627 }
628 void set_current_pending_monitor(ObjectMonitor* monitor) {
629 _current_pending_monitor = monitor;
630 }
631 void set_current_pending_monitor_is_from_java(bool from_java) {
632 _current_pending_monitor_is_from_java = from_java;
633 }
634 bool current_pending_monitor_is_from_java() {
635 return _current_pending_monitor_is_from_java;
636 }
637
638 // For tracking the ObjectMonitor on which this thread called Object.wait()
639 ObjectMonitor* current_waiting_monitor() {
640 return _current_waiting_monitor;
641 }
642 void set_current_waiting_monitor(ObjectMonitor* monitor) {
643 _current_waiting_monitor = monitor;
644 }
645
646 // For tracking the Jvmti raw monitor the thread is pending on.
647 JvmtiRawMonitor* current_pending_raw_monitor() {
648 return _current_pending_raw_monitor;
649 }
650 void set_current_pending_raw_monitor(JvmtiRawMonitor* monitor) {
651 _current_pending_raw_monitor = monitor;
652 }
653
654 // GC support
655 // Apply "f->do_oop" to all root oops in "this".
656 // Used by JavaThread::oops_do.
657 // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
658 virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
659
660 // Handles the parallel case for claim_threads_do.
661 private:
662 bool claim_par_threads_do(uintx claim_token);
663 public:
664 // Requires that "claim_token" is that of the current iteration.
665 // If "is_par" is false, sets the token of "this" to
666 // "claim_token", and returns "true". If "is_par" is true,
667 // uses an atomic instruction to set the current thread's token to
668 // "claim_token", if it is not already. Returns "true" iff the
669 // calling thread does the update, this indicates that the calling thread
670 // has claimed the thread in the current iteration.
671 bool claim_threads_do(bool is_par, uintx claim_token) {
672 if (!is_par) {
673 _threads_do_token = claim_token;
674 return true;
675 } else {
676 return claim_par_threads_do(claim_token);
677 }
678 }
679
680 uintx threads_do_token() const { return _threads_do_token; }
681
682 // jvmtiRedefineClasses support
683 void metadata_handles_do(void f(Metadata*));
684
685 private:
686 // Check if address is within the given range of this thread's
687 // stack: stack_base() > adr >/>= limit
688 // The check is inclusive of limit if passed true, else exclusive.
689 bool is_in_stack_range(address adr, address limit, bool inclusive) const {
690 assert(stack_base() > limit && limit >= stack_end(), "limit is outside of stack");
691 return stack_base() > adr && (inclusive ? adr >= limit : adr > limit);
692 }
693
694 public:
695 // Used by fast lock support
696 virtual bool is_lock_owned(address adr) const;
697
698 // Check if address is within the given range of this thread's
699 // stack: stack_base() > adr >= limit
700 bool is_in_stack_range_incl(address adr, address limit) const {
701 return is_in_stack_range(adr, limit, true);
702 }
703
704 // Check if address is within the given range of this thread's
705 // stack: stack_base() > adr > limit
706 bool is_in_stack_range_excl(address adr, address limit) const {
707 return is_in_stack_range(adr, limit, false);
708 }
709
710 // Check if address is in the stack mapped to this thread. Used mainly in
711 // error reporting (so has to include guard zone) and frame printing.
712 // Expects _stack_base to be initialized - checked with assert.
713 bool is_in_full_stack_checked(address adr) const {
714 return is_in_stack_range_incl(adr, stack_end());
715 }
716
717 // Like is_in_full_stack_checked but without the assertions as this
718 // may be called in a thread before _stack_base is initialized.
719 bool is_in_full_stack(address adr) const {
720 address stack_end = _stack_base - _stack_size;
721 return _stack_base > adr && adr >= stack_end;
722 }
723
724 // Check if address is in the live stack of this thread (not just for locks).
725 // Warning: can only be called by the current thread on itself.
726 bool is_in_live_stack(address adr) const {
727 assert(Thread::current() == this, "is_in_live_stack can only be called from current thread");
728 return is_in_stack_range_incl(adr, os::current_stack_pointer());
729 }
730
731 // Sets this thread as starting thread. Returns failure if thread
732 // creation fails due to lack of memory, too many threads etc.
733 bool set_as_starting_thread();
734
735 protected:
736 // OS data associated with the thread
737 OSThread* _osthread; // Platform-specific thread information
738
739 // Thread local resource area for temporary allocation within the VM
740 ResourceArea* _resource_area;
741
742 DEBUG_ONLY(ResourceMark* _current_resource_mark;)
743
744 // Thread local handle area for allocation of handles within the VM
745 HandleArea* _handle_area;
746 GrowableArray<Metadata*>* _metadata_handles;
747
748 // Support for stack overflow handling, get_thread, etc.
749 address _stack_base;
750 size_t _stack_size;
751 int _lgrp_id;
752
753 volatile void** polling_page_addr() { return &_polling_page; }
754
755 public:
756 // Stack overflow support
757 address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
758 void set_stack_base(address base) { _stack_base = base; }
759 size_t stack_size() const { return _stack_size; }
760 void set_stack_size(size_t size) { _stack_size = size; }
761 address stack_end() const { return stack_base() - stack_size(); }
762 void record_stack_base_and_size();
763 void register_thread_stack_with_NMT() NOT_NMT_RETURN;
764
765 int lgrp_id() const { return _lgrp_id; }
766 void set_lgrp_id(int value) { _lgrp_id = value; }
767
768 // Printing
769 void print_on(outputStream* st, bool print_extended_info) const;
770 virtual void print_on(outputStream* st) const { print_on(st, false); }
771 void print() const;
772 virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
773 void print_value_on(outputStream* st) const;
774
775 // Debug-only code
776 #ifdef ASSERT
777 private:
778 // Deadlock detection support for Mutex locks. List of locks own by thread.
779 Mutex* _owned_locks;
780 // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
781 // thus the friendship
782 friend class Mutex;
783 friend class Monitor;
784
785 public:
786 void print_owned_locks_on(outputStream* st) const;
787 void print_owned_locks() const { print_owned_locks_on(tty); }
788 Mutex* owned_locks() const { return _owned_locks; }
789 bool owns_locks() const { return owned_locks() != NULL; }
790
791 // Deadlock detection
792 ResourceMark* current_resource_mark() { return _current_resource_mark; }
793 void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
794 #endif // ASSERT
795
796 // These functions check conditions on a JavaThread before possibly going to a safepoint,
797 // including NoSafepointVerifier.
798 void check_for_valid_safepoint_state() NOT_DEBUG_RETURN;
799 void check_possible_safepoint() NOT_DEBUG_RETURN;
800
801 private:
802 volatile int _jvmti_env_iteration_count;
803
804 public:
805 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; }
806 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; }
807 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; }
808
809 // Code generation
810 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file); }
811 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line); }
812 static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles); }
813
814 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base); }
815 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size); }
816
817 static ByteSize polling_page_offset() { return byte_offset_of(Thread, _polling_page); }
818
819 static ByteSize tlab_start_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); }
820 static ByteSize tlab_end_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); }
821 static ByteSize tlab_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); }
822 static ByteSize tlab_pf_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); }
823
824 static ByteSize allocated_bytes_offset() { return byte_offset_of(Thread, _allocated_bytes); }
825
826 JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
827
828 public:
829 volatile intptr_t _Stalled;
830 volatile int _TypeTag;
831 ParkEvent * _ParkEvent; // for Object monitors and JVMTI raw monitors
832 ParkEvent * _MuxEvent; // for low-level muxAcquire-muxRelease
833 int NativeSyncRecursion; // diagnostic
834
835 volatile int _OnTrap; // Resume-at IP delta
836 jint _hashStateW; // Marsaglia Shift-XOR thread-local RNG
837 jint _hashStateX; // thread-specific hashCode generator state
838 jint _hashStateY;
839 jint _hashStateZ;
840
841 // Low-level leaf-lock primitives used to implement synchronization
842 // and native monitor-mutex infrastructure.
843 // Not for general synchronization use.
844 static void SpinAcquire(volatile int * Lock, const char * Name);
845 static void SpinRelease(volatile int * Lock);
846 static void muxAcquire(volatile intptr_t * Lock, const char * Name);
847 static void muxRelease(volatile intptr_t * Lock);
848 };
849
850 // Inline implementation of Thread::current()
851 inline Thread* Thread::current() {
852 Thread* current = current_or_null();
853 assert(current != NULL, "Thread::current() called on detached thread");
854 return current;
855 }
856
857 inline Thread* Thread::current_or_null() {
858 #ifndef USE_LIBRARY_BASED_TLS_ONLY
859 return _thr_current;
860 #else
861 if (ThreadLocalStorage::is_initialized()) {
862 return ThreadLocalStorage::thread();
863 }
864 return NULL;
865 #endif
866 }
867
868 inline Thread* Thread::current_or_null_safe() {
869 if (ThreadLocalStorage::is_initialized()) {
870 return ThreadLocalStorage::thread();
871 }
872 return NULL;
873 }
874
875 class NonJavaThread: public Thread {
876 friend class VMStructs;
877
878 NonJavaThread* volatile _next;
879
880 class List;
881 static List _the_list;
882
883 void add_to_the_list();
884 void remove_from_the_list();
885
886 protected:
887 virtual void pre_run();
888 virtual void post_run();
889
890 public:
891 NonJavaThread();
892 ~NonJavaThread();
893
894 class Iterator;
895 };
896
897 // Provides iteration over the list of NonJavaThreads.
898 // List addition occurs in pre_run(), and removal occurs in post_run(),
899 // so that only live fully-initialized threads can be found in the list.
900 // Threads created after an iterator is constructed will not be visited
901 // by the iterator. The scope of an iterator is a critical section; there
902 // must be no safepoint checks in that scope.
903 class NonJavaThread::Iterator : public StackObj {
904 uint _protect_enter;
905 NonJavaThread* _current;
906
907 NONCOPYABLE(Iterator);
908
909 public:
910 Iterator();
911 ~Iterator();
912
913 bool end() const { return _current == NULL; }
914 NonJavaThread* current() const { return _current; }
915 void step();
916 };
917
918 // Name support for threads. non-JavaThread subclasses with multiple
919 // uniquely named instances should derive from this.
920 class NamedThread: public NonJavaThread {
921 friend class VMStructs;
922 enum {
923 max_name_len = 64
924 };
925 private:
926 char* _name;
927 // log JavaThread being processed by oops_do
928 JavaThread* _processed_thread;
929 uint _gc_id; // The current GC id when a thread takes part in GC
930
931 public:
932 NamedThread();
933 ~NamedThread();
934 // May only be called once per thread.
935 void set_name(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
936 virtual bool is_Named_thread() const { return true; }
937 virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
938 JavaThread *processed_thread() { return _processed_thread; }
939 void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
940 virtual void print_on(outputStream* st) const;
941
942 void set_gc_id(uint gc_id) { _gc_id = gc_id; }
943 uint gc_id() { return _gc_id; }
944 };
945
946 // Worker threads are named and have an id of an assigned work.
947 class WorkerThread: public NamedThread {
948 private:
949 uint _id;
950 public:
951 WorkerThread() : _id(0) { }
952 virtual bool is_Worker_thread() const { return true; }
953
954 virtual WorkerThread* as_Worker_thread() const {
955 assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
956 return (WorkerThread*) this;
957 }
958
959 void set_id(uint work_id) { _id = work_id; }
960 uint id() const { return _id; }
961 };
962
963 // A single WatcherThread is used for simulating timer interrupts.
964 class WatcherThread: public NonJavaThread {
965 friend class VMStructs;
966 protected:
967 virtual void run();
968
969 private:
970 static WatcherThread* _watcher_thread;
971
972 static bool _startable;
973 // volatile due to at least one lock-free read
974 volatile static bool _should_terminate;
975 public:
976 enum SomeConstants {
977 delay_interval = 10 // interrupt delay in milliseconds
978 };
979
980 // Constructor
981 WatcherThread();
982
983 // No destruction allowed
984 ~WatcherThread() {
985 guarantee(false, "WatcherThread deletion must fix the race with VM termination");
986 }
987
988 // Tester
989 bool is_Watcher_thread() const { return true; }
990
991 // Printing
992 char* name() const { return (char*)"VM Periodic Task Thread"; }
993 void print_on(outputStream* st) const;
994 void unpark();
995
996 // Returns the single instance of WatcherThread
997 static WatcherThread* watcher_thread() { return _watcher_thread; }
998
999 // Create and start the single instance of WatcherThread, or stop it on shutdown
1000 static void start();
1001 static void stop();
1002 // Only allow start once the VM is sufficiently initialized
1003 // Otherwise the first task to enroll will trigger the start
1004 static void make_startable();
1005 private:
1006 int sleep() const;
1007 };
1008
1009
1010 class CompilerThread;
1011
1012 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
1013
1014 class JavaThread: public Thread {
1015 friend class VMStructs;
1016 friend class JVMCIVMStructs;
1017 friend class WhiteBox;
1018 friend class VTBuffer;
1019 friend class ThreadsSMRSupport; // to access _threadObj for exiting_threads_oops_do
1020 private:
1021 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
1022 oop _threadObj; // The Java level thread object
1023
1024 #ifdef ASSERT
1025 private:
1026 int _java_call_counter;
1027
1028 public:
1029 int java_call_counter() { return _java_call_counter; }
1030 void inc_java_call_counter() { _java_call_counter++; }
1031 void dec_java_call_counter() {
1032 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
1033 _java_call_counter--;
1034 }
1035 private: // restore original namespace restriction
1036 #endif // ifdef ASSERT
1037
1038 #ifndef PRODUCT
1039 public:
1040 enum {
1041 jump_ring_buffer_size = 16
1042 };
1043 private: // restore original namespace restriction
1044 #endif
1045
1046 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
1047
1048 ThreadFunction _entry_point;
1049
1050 JNIEnv _jni_environment;
1051
1052 // Deopt support
1053 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
1054
1055 CompiledMethod* _deopt_nmethod; // CompiledMethod that is currently being deoptimized
1056 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
1057 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
1058 // Because deoptimization is lazy we must save jvmti requests to set locals
1059 // in compiled frames until we deoptimize and we have an interpreter frame.
1060 // This holds the pointer to array (yeah like there might be more than one) of
1061 // description of compiled vframes that have locals that need to be updated.
1062 GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
1063
1064 // Handshake value for fixing 6243940. We need a place for the i2c
1065 // adapter to store the callee Method*. This value is NEVER live
1066 // across a gc point so it does NOT have to be gc'd
1067 // The handshake is open ended since we can't be certain that it will
1068 // be NULLed. This is because we rarely ever see the race and end up
1069 // in handle_wrong_method which is the backend of the handshake. See
1070 // code in i2c adapters and handle_wrong_method.
1071
1072 Method* _callee_target;
1073
1074 // Used to pass back results to the interpreter or generated code running Java code.
1075 oop _vm_result; // oop result is GC-preserved
1076 Metadata* _vm_result_2; // non-oop result
1077 oop _return_buffered_value; // buffered value being returned
1078
1079 // See ReduceInitialCardMarks: this holds the precise space interval of
1080 // the most recent slow path allocation for which compiled code has
1081 // elided card-marks for performance along the fast-path.
1082 MemRegion _deferred_card_mark;
1083
1084 MonitorChunk* _monitor_chunks; // Contains the off stack monitors
1085 // allocated during deoptimization
1086 // and by JNI_MonitorEnter/Exit
1087
1088 // Async. requests support
1089 enum AsyncRequests {
1090 _no_async_condition = 0,
1091 _async_exception,
1092 _async_unsafe_access_error
1093 };
1094 AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
1095 oop _pending_async_exception;
1096
1097 // Safepoint support
1098 public: // Expose _thread_state for SafeFetchInt()
1099 volatile JavaThreadState _thread_state;
1100 private:
1101 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint
1102 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
1103
1104 // JavaThread termination support
1105 enum TerminatedTypes {
1106 _not_terminated = 0xDEAD - 2,
1107 _thread_exiting, // JavaThread::exit() has been called for this thread
1108 _thread_terminated, // JavaThread is removed from thread list
1109 _vm_exited // JavaThread is still executing native code, but VM is terminated
1110 // only VM_Exit can set _vm_exited
1111 };
1112
1113 // In general a JavaThread's _terminated field transitions as follows:
1114 //
1115 // _not_terminated => _thread_exiting => _thread_terminated
1116 //
1117 // _vm_exited is a special value to cover the case of a JavaThread
1118 // executing native code after the VM itself is terminated.
1119 volatile TerminatedTypes _terminated;
1120 // suspend/resume support
1121 volatile bool _suspend_equivalent; // Suspend equivalent condition
1122 jint _in_deopt_handler; // count of deoptimization
1123 // handlers thread is in
1124 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
1125 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
1126 // never locked) when throwing an exception. Used by interpreter only.
1127
1128 // JNI attach states:
1129 enum JNIAttachStates {
1130 _not_attaching_via_jni = 1, // thread is not attaching via JNI
1131 _attaching_via_jni, // thread is attaching via JNI
1132 _attached_via_jni // thread has attached via JNI
1133 };
1134
1135 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
1136 // A native thread that is attaching via JNI starts with a value
1137 // of _attaching_via_jni and transitions to _attached_via_jni.
1138 volatile JNIAttachStates _jni_attach_state;
1139
1140 public:
1141 // State of the stack guard pages for this thread.
1142 enum StackGuardState {
1143 stack_guard_unused, // not needed
1144 stack_guard_reserved_disabled,
1145 stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
1146 stack_guard_enabled // enabled
1147 };
1148
1149 private:
1150
1151 #if INCLUDE_JVMCI
1152 // The _pending_* fields below are used to communicate extra information
1153 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
1154
1155 // Communicates the DeoptReason and DeoptAction of the uncommon trap
1156 int _pending_deoptimization;
1157
1158 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
1159 // before the monitor has been acquired.
1160 bool _pending_monitorenter;
1161
1162 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
1163 bool _pending_transfer_to_interpreter;
1164
1165 // True if in a runtime call from compiled code that will deoptimize
1166 // and re-execute a failed heap allocation in the interpreter.
1167 bool _in_retryable_allocation;
1168
1169 // An id of a speculation that JVMCI compiled code can use to further describe and
1170 // uniquely identify the speculative optimization guarded by the uncommon trap
1171 jlong _pending_failed_speculation;
1172
1173 // These fields are mutually exclusive in terms of live ranges.
1174 union {
1175 // Communicates the pc at which the most recent implicit exception occurred
1176 // from the signal handler to a deoptimization stub.
1177 address _implicit_exception_pc;
1178
1179 // Communicates an alternative call target to an i2c stub from a JavaCall .
1180 address _alternate_call_target;
1181 } _jvmci;
1182
1183 // Support for high precision, thread sensitive counters in JVMCI compiled code.
1184 jlong* _jvmci_counters;
1185
1186 public:
1187 static jlong* _jvmci_old_thread_counters;
1188 static void collect_counters(jlong* array, int length);
1189 void resize_counters(int current_size, int new_size);
1190 static void resize_all_jvmci_counters(int new_size);
1191
1192 private:
1193 #endif // INCLUDE_JVMCI
1194
1195 StackGuardState _stack_guard_state;
1196
1197 // Precompute the limit of the stack as used in stack overflow checks.
1198 // We load it from here to simplify the stack overflow check in assembly.
1199 address _stack_overflow_limit;
1200 address _reserved_stack_activation;
1201
1202 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1203 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1204 // code)
1205 volatile oop _exception_oop; // Exception thrown in compiled code
1206 volatile address _exception_pc; // PC where exception happened
1207 volatile address _exception_handler_pc; // PC for handler of exception
1208 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
1209
1210 private:
1211 // support for JNI critical regions
1212 jint _jni_active_critical; // count of entries into JNI critical region
1213
1214 // Checked JNI: function name requires exception check
1215 char* _pending_jni_exception_check_fn;
1216
1217 // For deadlock detection.
1218 int _depth_first_number;
1219
1220 // JVMTI PopFrame support
1221 // This is set to popframe_pending to signal that top Java frame should be popped immediately
1222 int _popframe_condition;
1223
1224 // If reallocation of scalar replaced objects fails, we throw OOM
1225 // and during exception propagation, pop the top
1226 // _frames_to_pop_failed_realloc frames, the ones that reference
1227 // failed reallocations.
1228 int _frames_to_pop_failed_realloc;
1229
1230 friend class VMThread;
1231 friend class ThreadWaitTransition;
1232 friend class VM_Exit;
1233
1234 void initialize(); // Initialized the instance variables
1235
1236 public:
1237 // Constructor
1238 JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1239 JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1240 ~JavaThread();
1241
1242 #ifdef ASSERT
1243 // verify this JavaThread hasn't be published in the Threads::list yet
1244 void verify_not_published();
1245 #endif // ASSERT
1246
1247 //JNI functiontable getter/setter for JVMTI jni function table interception API.
1248 void set_jni_functions(struct JNINativeInterface_* functionTable) {
1249 _jni_environment.functions = functionTable;
1250 }
1251 struct JNINativeInterface_* get_jni_functions() {
1252 return (struct JNINativeInterface_ *)_jni_environment.functions;
1253 }
1254
1255 // This function is called at thread creation to allow
1256 // platform specific thread variables to be initialized.
1257 void cache_global_variables();
1258
1259 // Executes Shutdown.shutdown()
1260 void invoke_shutdown_hooks();
1261
1262 // Cleanup on thread exit
1263 enum ExitType {
1264 normal_exit,
1265 jni_detach
1266 };
1267 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1268
1269 void cleanup_failed_attach_current_thread(bool is_daemon);
1270
1271 // Testers
1272 virtual bool is_Java_thread() const { return true; }
1273 virtual bool can_call_java() const { return true; }
1274
1275 virtual bool is_active_Java_thread() const {
1276 return on_thread_list() && !is_terminated();
1277 }
1278
1279 // Thread oop. threadObj() can be NULL for initial JavaThread
1280 // (or for threads attached via JNI)
1281 oop threadObj() const { return _threadObj; }
1282 void set_threadObj(oop p) { _threadObj = p; }
1283
1284 // Prepare thread and add to priority queue. If a priority is
1285 // not specified, use the priority of the thread object. Threads_lock
1286 // must be held while this function is called.
1287 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1288
1289 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
1290 address saved_exception_pc() { return _saved_exception_pc; }
1291
1292
1293 ThreadFunction entry_point() const { return _entry_point; }
1294
1295 // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1296 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1297
1298 // Last frame anchor routines
1299
1300 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
1301
1302 // last_Java_sp
1303 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
1304 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
1305
1306 // last_Java_pc
1307
1308 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
1309
1310 // Safepoint support
1311 inline JavaThreadState thread_state() const;
1312 inline void set_thread_state(JavaThreadState s);
1313 inline void set_thread_state_fence(JavaThreadState s); // fence after setting thread state
1314 inline ThreadSafepointState* safepoint_state() const;
1315 inline void set_safepoint_state(ThreadSafepointState* state);
1316 inline bool is_at_poll_safepoint();
1317
1318 // JavaThread termination and lifecycle support:
1319 void smr_delete();
1320 bool on_thread_list() const { return _on_thread_list; }
1321 void set_on_thread_list() { _on_thread_list = true; }
1322
1323 // thread has called JavaThread::exit() or is terminated
1324 bool is_exiting() const;
1325 // thread is terminated (no longer on the threads list); we compare
1326 // against the two non-terminated values so that a freed JavaThread
1327 // will also be considered terminated.
1328 bool check_is_terminated(TerminatedTypes l_terminated) const {
1329 return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1330 }
1331 bool is_terminated() const;
1332 void set_terminated(TerminatedTypes t);
1333 // special for Threads::remove() which is static:
1334 void set_terminated_value();
1335 void block_if_vm_exited();
1336
1337 bool doing_unsafe_access() { return _doing_unsafe_access; }
1338 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
1339
1340 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
1341 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1342
1343 inline void set_polling_page_release(void* poll_value);
1344 inline void set_polling_page(void* poll_value);
1345 inline volatile void* get_polling_page();
1346
1347 private:
1348 // Support for thread handshake operations
1349 HandshakeState _handshake;
1350 public:
1351 void set_handshake_operation(HandshakeOperation* op) {
1352 _handshake.set_operation(op);
1353 }
1354
1355 bool has_handshake() const {
1356 return _handshake.has_operation();
1357 }
1358
1359 void handshake_process_by_self() {
1360 _handshake.process_by_self();
1361 }
1362
1363 HandshakeState::ProcessResult handshake_try_process(HandshakeOperation* op) {
1364 return _handshake.try_process(op);
1365 }
1366
1367 #ifdef ASSERT
1368 Thread* active_handshaker() const {
1369 return _handshake.active_handshaker();
1370 }
1371 #endif
1372
1373 // Suspend/resume support for JavaThread
1374 private:
1375 inline void set_ext_suspended();
1376 inline void clear_ext_suspended();
1377
1378 public:
1379 void java_suspend(); // higher-level suspension logic called by the public APIs
1380 void java_resume(); // higher-level resume logic called by the public APIs
1381 int java_suspend_self(); // low-level self-suspension mechanics
1382
1383 private:
1384 // mid-level wrapper around java_suspend_self to set up correct state and
1385 // check for a pending safepoint at the end
1386 void java_suspend_self_with_safepoint_check();
1387
1388 public:
1389 void check_and_wait_while_suspended() {
1390 assert(JavaThread::current() == this, "sanity check");
1391
1392 bool do_self_suspend;
1393 do {
1394 // were we externally suspended while we were waiting?
1395 do_self_suspend = handle_special_suspend_equivalent_condition();
1396 if (do_self_suspend) {
1397 // don't surprise the thread that suspended us by returning
1398 java_suspend_self();
1399 set_suspend_equivalent();
1400 }
1401 } while (do_self_suspend);
1402 }
1403 static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1404 // Check for async exception in addition to safepoint and suspend request.
1405 static void check_special_condition_for_native_trans(JavaThread *thread);
1406
1407 // Same as check_special_condition_for_native_trans but finishes the
1408 // transition into thread_in_Java mode so that it can potentially
1409 // block.
1410 static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1411
1412 bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1413 bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1414 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1415 // Warning: is_ext_suspend_completed() may temporarily drop the
1416 // SR_lock to allow the thread to reach a stable thread state if
1417 // it is currently in a transient thread state.
1418 return is_ext_suspend_completed(false /* !called_by_wait */,
1419 SuspendRetryDelay, bits);
1420 }
1421
1422 // We cannot allow wait_for_ext_suspend_completion() to run forever or
1423 // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1424 // passed as the count and delay parameters. Experiments with specific
1425 // calls to wait_for_ext_suspend_completion() can be done by passing
1426 // other values in the code. Experiments with all calls can be done
1427 // via the appropriate -XX options.
1428 bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1429
1430 // test for suspend - most (all?) of these should go away
1431 bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits);
1432
1433 inline void set_external_suspend();
1434 inline void clear_external_suspend();
1435
1436 bool is_external_suspend() const {
1437 return (_suspend_flags & _external_suspend) != 0;
1438 }
1439 // Whenever a thread transitions from native to vm/java it must suspend
1440 // if external|deopt suspend is present.
1441 bool is_suspend_after_native() const {
1442 return (_suspend_flags & (_external_suspend JFR_ONLY(| _trace_flag))) != 0;
1443 }
1444
1445 // external suspend request is completed
1446 bool is_ext_suspended() const {
1447 return (_suspend_flags & _ext_suspended) != 0;
1448 }
1449
1450 bool is_external_suspend_with_lock() const {
1451 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1452 return is_external_suspend();
1453 }
1454
1455 // Special method to handle a pending external suspend request
1456 // when a suspend equivalent condition lifts.
1457 bool handle_special_suspend_equivalent_condition() {
1458 assert(is_suspend_equivalent(),
1459 "should only be called in a suspend equivalence condition");
1460 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1461 bool ret = is_external_suspend();
1462 if (!ret) {
1463 // not about to self-suspend so clear suspend equivalence
1464 clear_suspend_equivalent();
1465 }
1466 // implied else:
1467 // We have a pending external suspend request so we leave the
1468 // suspend_equivalent flag set until java_suspend_self() sets
1469 // the ext_suspended flag and clears the suspend_equivalent
1470 // flag. This insures that wait_for_ext_suspend_completion()
1471 // will return consistent values.
1472 return ret;
1473 }
1474
1475 // utility methods to see if we are doing some kind of suspension
1476 bool is_being_ext_suspended() const {
1477 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1478 return is_ext_suspended() || is_external_suspend();
1479 }
1480
1481 bool is_suspend_equivalent() const { return _suspend_equivalent; }
1482
1483 void set_suspend_equivalent() { _suspend_equivalent = true; }
1484 void clear_suspend_equivalent() { _suspend_equivalent = false; }
1485
1486 // Thread.stop support
1487 void send_thread_stop(oop throwable);
1488 AsyncRequests clear_special_runtime_exit_condition() {
1489 AsyncRequests x = _special_runtime_exit_condition;
1490 _special_runtime_exit_condition = _no_async_condition;
1491 return x;
1492 }
1493
1494 // Are any async conditions present?
1495 bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1496
1497 void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1498
1499 // these next two are also used for self-suspension and async exception support
1500 void handle_special_runtime_exit_condition(bool check_asyncs = true);
1501
1502 // Return true if JavaThread has an asynchronous condition or
1503 // if external suspension is requested.
1504 bool has_special_runtime_exit_condition() {
1505 // Because we don't use is_external_suspend_with_lock
1506 // it is possible that we won't see an asynchronous external suspend
1507 // request that has just gotten started, i.e., SR_lock grabbed but
1508 // _external_suspend field change either not made yet or not visible
1509 // yet. However, this is okay because the request is asynchronous and
1510 // we will see the new flag value the next time through. It's also
1511 // possible that the external suspend request is dropped after
1512 // we have checked is_external_suspend(), we will recheck its value
1513 // under SR_lock in java_suspend_self().
1514 return (_special_runtime_exit_condition != _no_async_condition) ||
1515 is_external_suspend() || is_trace_suspend();
1516 }
1517
1518 void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; }
1519
1520 inline void set_pending_async_exception(oop e);
1521
1522 // Fast-locking support
1523 bool is_lock_owned(address adr) const;
1524
1525 // Accessors for vframe array top
1526 // The linked list of vframe arrays are sorted on sp. This means when we
1527 // unpack the head must contain the vframe array to unpack.
1528 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1529 vframeArray* vframe_array_head() const { return _vframe_array_head; }
1530
1531 // Side structure for deferring update of java frame locals until deopt occurs
1532 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1533 void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1534
1535 // These only really exist to make debugging deopt problems simpler
1536
1537 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1538 vframeArray* vframe_array_last() const { return _vframe_array_last; }
1539
1540 // The special resourceMark used during deoptimization
1541
1542 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
1543 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
1544
1545 void set_deopt_compiled_method(CompiledMethod* nm) { _deopt_nmethod = nm; }
1546 CompiledMethod* deopt_compiled_method() { return _deopt_nmethod; }
1547
1548 Method* callee_target() const { return _callee_target; }
1549 void set_callee_target (Method* x) { _callee_target = x; }
1550
1551 // Oop results of vm runtime calls
1552 oop vm_result() const { return _vm_result; }
1553 void set_vm_result (oop x) { _vm_result = x; }
1554
1555 Metadata* vm_result_2() const { return _vm_result_2; }
1556 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
1557
1558 oop return_buffered_value() const { return _return_buffered_value; }
1559 void set_return_buffered_value(oop val) { _return_buffered_value = val; }
1560
1561 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
1562 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
1563
1564 #if INCLUDE_JVMCI
1565 int pending_deoptimization() const { return _pending_deoptimization; }
1566 jlong pending_failed_speculation() const { return _pending_failed_speculation; }
1567 bool has_pending_monitorenter() const { return _pending_monitorenter; }
1568 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
1569 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
1570 void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; }
1571 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1572 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1573 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1574
1575 virtual bool in_retryable_allocation() const { return _in_retryable_allocation; }
1576 void set_in_retryable_allocation(bool b) { _in_retryable_allocation = b; }
1577 #endif // INCLUDE_JVMCI
1578
1579 // Exception handling for compiled methods
1580 oop exception_oop() const;
1581 address exception_pc() const { return _exception_pc; }
1582 address exception_handler_pc() const { return _exception_handler_pc; }
1583 bool is_method_handle_return() const { return _is_method_handle_return == 1; }
1584
1585 void set_exception_oop(oop o);
1586 void set_exception_pc(address a) { _exception_pc = a; }
1587 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
1588 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
1589
1590 void clear_exception_oop_and_pc() {
1591 set_exception_oop(NULL);
1592 set_exception_pc(NULL);
1593 }
1594
1595 // Stack overflow support
1596 //
1597 // (small addresses)
1598 //
1599 // -- <-- stack_end() ---
1600 // | |
1601 // | red pages |
1602 // | |
1603 // -- <-- stack_red_zone_base() |
1604 // | |
1605 // | guard
1606 // | yellow pages zone
1607 // | |
1608 // | |
1609 // -- <-- stack_yellow_zone_base() |
1610 // | |
1611 // | |
1612 // | reserved pages |
1613 // | |
1614 // -- <-- stack_reserved_zone_base() --- ---
1615 // /|\ shadow <-- stack_overflow_limit() (somewhere in here)
1616 // | zone
1617 // \|/ size
1618 // some untouched memory ---
1619 //
1620 //
1621 // --
1622 // |
1623 // | shadow zone
1624 // |
1625 // --
1626 // x frame n
1627 // --
1628 // x frame n-1
1629 // x
1630 // --
1631 // ...
1632 //
1633 // --
1634 // x frame 0
1635 // -- <-- stack_base()
1636 //
1637 // (large addresses)
1638 //
1639
1640 private:
1641 // These values are derived from flags StackRedPages, StackYellowPages,
1642 // StackReservedPages and StackShadowPages. The zone size is determined
1643 // ergonomically if page_size > 4K.
1644 static size_t _stack_red_zone_size;
1645 static size_t _stack_yellow_zone_size;
1646 static size_t _stack_reserved_zone_size;
1647 static size_t _stack_shadow_zone_size;
1648 public:
1649 inline size_t stack_available(address cur_sp);
1650
1651 static size_t stack_red_zone_size() {
1652 assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1653 return _stack_red_zone_size;
1654 }
1655 static void set_stack_red_zone_size(size_t s) {
1656 assert(is_aligned(s, os::vm_page_size()),
1657 "We can not protect if the red zone size is not page aligned.");
1658 assert(_stack_red_zone_size == 0, "This should be called only once.");
1659 _stack_red_zone_size = s;
1660 }
1661 address stack_red_zone_base() {
1662 return (address)(stack_end() + stack_red_zone_size());
1663 }
1664 bool in_stack_red_zone(address a) {
1665 return a <= stack_red_zone_base() && a >= stack_end();
1666 }
1667
1668 static size_t stack_yellow_zone_size() {
1669 assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1670 return _stack_yellow_zone_size;
1671 }
1672 static void set_stack_yellow_zone_size(size_t s) {
1673 assert(is_aligned(s, os::vm_page_size()),
1674 "We can not protect if the yellow zone size is not page aligned.");
1675 assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1676 _stack_yellow_zone_size = s;
1677 }
1678
1679 static size_t stack_reserved_zone_size() {
1680 // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1681 return _stack_reserved_zone_size;
1682 }
1683 static void set_stack_reserved_zone_size(size_t s) {
1684 assert(is_aligned(s, os::vm_page_size()),
1685 "We can not protect if the reserved zone size is not page aligned.");
1686 assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1687 _stack_reserved_zone_size = s;
1688 }
1689 address stack_reserved_zone_base() const {
1690 return (address)(stack_end() +
1691 (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1692 }
1693 bool in_stack_reserved_zone(address a) {
1694 return (a <= stack_reserved_zone_base()) &&
1695 (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1696 }
1697
1698 static size_t stack_yellow_reserved_zone_size() {
1699 return _stack_yellow_zone_size + _stack_reserved_zone_size;
1700 }
1701 bool in_stack_yellow_reserved_zone(address a) {
1702 return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1703 }
1704
1705 // Size of red + yellow + reserved zones.
1706 static size_t stack_guard_zone_size() {
1707 return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1708 }
1709
1710 static size_t stack_shadow_zone_size() {
1711 assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1712 return _stack_shadow_zone_size;
1713 }
1714 static void set_stack_shadow_zone_size(size_t s) {
1715 // The shadow area is not allocated or protected, so
1716 // it needs not be page aligned.
1717 // But the stack bang currently assumes that it is a
1718 // multiple of page size. This guarantees that the bang
1719 // loop touches all pages in the shadow zone.
1720 // This can be guaranteed differently, as well. E.g., if
1721 // the page size is a multiple of 4K, banging in 4K steps
1722 // suffices to touch all pages. (Some pages are banged
1723 // several times, though.)
1724 assert(is_aligned(s, os::vm_page_size()),
1725 "Stack bang assumes multiple of page size.");
1726 assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1727 _stack_shadow_zone_size = s;
1728 }
1729
1730 void create_stack_guard_pages();
1731 void remove_stack_guard_pages();
1732
1733 void enable_stack_reserved_zone();
1734 void disable_stack_reserved_zone();
1735 void enable_stack_yellow_reserved_zone();
1736 void disable_stack_yellow_reserved_zone();
1737 void enable_stack_red_zone();
1738 void disable_stack_red_zone();
1739
1740 inline bool stack_guard_zone_unused();
1741 inline bool stack_yellow_reserved_zone_disabled();
1742 inline bool stack_reserved_zone_disabled();
1743 inline bool stack_guards_enabled();
1744
1745 address reserved_stack_activation() const { return _reserved_stack_activation; }
1746 void set_reserved_stack_activation(address addr) {
1747 assert(_reserved_stack_activation == stack_base()
1748 || _reserved_stack_activation == NULL
1749 || addr == stack_base(), "Must not be set twice");
1750 _reserved_stack_activation = addr;
1751 }
1752
1753 // Attempt to reguard the stack after a stack overflow may have occurred.
1754 // Returns true if (a) guard pages are not needed on this thread, (b) the
1755 // pages are already guarded, or (c) the pages were successfully reguarded.
1756 // Returns false if there is not enough stack space to reguard the pages, in
1757 // which case the caller should unwind a frame and try again. The argument
1758 // should be the caller's (approximate) sp.
1759 bool reguard_stack(address cur_sp);
1760 // Similar to above but see if current stackpoint is out of the guard area
1761 // and reguard if possible.
1762 bool reguard_stack(void);
1763
1764 address stack_overflow_limit() { return _stack_overflow_limit; }
1765 void set_stack_overflow_limit() {
1766 _stack_overflow_limit =
1767 stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1768 }
1769
1770 // Check if address is in the usable part of the stack (excludes protected
1771 // guard pages). Can be applied to any thread and is an approximation for
1772 // using is_in_live_stack when the query has to happen from another thread.
1773 bool is_in_usable_stack(address adr) const {
1774 return is_in_stack_range_incl(adr, stack_reserved_zone_base());
1775 }
1776
1777 // Misc. accessors/mutators
1778 void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; }
1779 void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; }
1780 bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; }
1781
1782 // For assembly stub generation
1783 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
1784 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
1785 static ByteSize pending_jni_exception_check_fn_offset() {
1786 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1787 }
1788 static ByteSize last_Java_sp_offset() {
1789 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1790 }
1791 static ByteSize last_Java_pc_offset() {
1792 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1793 }
1794 static ByteSize frame_anchor_offset() {
1795 return byte_offset_of(JavaThread, _anchor);
1796 }
1797 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
1798 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); }
1799 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); }
1800 static ByteSize return_buffered_value_offset() { return byte_offset_of(JavaThread, _return_buffered_value); }
1801 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
1802 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
1803 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
1804 #if INCLUDE_JVMCI
1805 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1806 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
1807 static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1808 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1809 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1810 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
1811 #endif // INCLUDE_JVMCI
1812 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
1813 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
1814 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
1815 static ByteSize stack_overflow_limit_offset() { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1816 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1817 static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state); }
1818 static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1819 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
1820
1821 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1822 static ByteSize should_post_on_exceptions_flag_offset() {
1823 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1824 }
1825 static ByteSize doing_unsafe_access_offset() { return byte_offset_of(JavaThread, _doing_unsafe_access); }
1826
1827 // Returns the jni environment for this thread
1828 JNIEnv* jni_environment() { return &_jni_environment; }
1829
1830 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1831 JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1832 // Only return NULL if thread is off the thread list; starting to
1833 // exit should not return NULL.
1834 if (thread_from_jni_env->is_terminated()) {
1835 thread_from_jni_env->block_if_vm_exited();
1836 return NULL;
1837 } else {
1838 return thread_from_jni_env;
1839 }
1840 }
1841
1842 // JNI critical regions. These can nest.
1843 bool in_critical() { return _jni_active_critical > 0; }
1844 bool in_last_critical() { return _jni_active_critical == 1; }
1845 inline void enter_critical();
1846 void exit_critical() {
1847 assert(Thread::current() == this, "this must be current thread");
1848 _jni_active_critical--;
1849 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1850 }
1851
1852 // Checked JNI: is the programmer required to check for exceptions, if so specify
1853 // which function name. Returning to a Java frame should implicitly clear the
1854 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1855 // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1856 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1857 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1858 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1859 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1860 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1861
1862 // For deadlock detection
1863 int depth_first_number() { return _depth_first_number; }
1864 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1865
1866 private:
1867 void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1868
1869 public:
1870 MonitorChunk* monitor_chunks() const { return _monitor_chunks; }
1871 void add_monitor_chunk(MonitorChunk* chunk);
1872 void remove_monitor_chunk(MonitorChunk* chunk);
1873 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
1874 void inc_in_deopt_handler() { _in_deopt_handler++; }
1875 void dec_in_deopt_handler() {
1876 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1877 if (_in_deopt_handler > 0) { // robustness
1878 _in_deopt_handler--;
1879 }
1880 }
1881
1882 private:
1883 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1884
1885 public:
1886
1887 // Frame iteration; calls the function f for all frames on the stack
1888 void frames_do(void f(frame*, const RegisterMap*));
1889
1890 // Memory operations
1891 void oops_do(OopClosure* f, CodeBlobClosure* cf);
1892
1893 // Sweeper operations
1894 virtual void nmethods_do(CodeBlobClosure* cf);
1895
1896 // RedefineClasses Support
1897 void metadata_do(MetadataClosure* f);
1898
1899 // Debug method asserting thread states are correct during a handshake operation.
1900 DEBUG_ONLY(void verify_states_for_handshake();)
1901
1902 // Misc. operations
1903 char* name() const { return (char*)get_thread_name(); }
1904 void print_on(outputStream* st, bool print_extended_info) const;
1905 void print_on(outputStream* st) const { print_on(st, false); }
1906 void print() const;
1907 void print_thread_state_on(outputStream*) const PRODUCT_RETURN;
1908 void print_on_error(outputStream* st, char* buf, int buflen) const;
1909 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1910 void verify();
1911 const char* get_thread_name() const;
1912 protected:
1913 // factor out low-level mechanics for use in both normal and error cases
1914 virtual const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1915 public:
1916 // Accessing frames
1917 frame last_frame() {
1918 _anchor.make_walkable(this);
1919 return pd_last_frame();
1920 }
1921 javaVFrame* last_java_vframe(RegisterMap* reg_map);
1922
1923 // Returns method at 'depth' java or native frames down the stack
1924 // Used for security checks
1925 Klass* security_get_caller_class(int depth);
1926
1927 // Print stack trace in external format
1928 void print_stack_on(outputStream* st);
1929 void print_stack() { print_stack_on(tty); }
1930
1931 // Print stack traces in various internal formats
1932 void trace_stack() PRODUCT_RETURN;
1933 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1934 void trace_frames() PRODUCT_RETURN;
1935
1936 // Print an annotated view of the stack frames
1937 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1938 void validate_frame_layout() {
1939 print_frame_layout(0, true);
1940 }
1941
1942 // Function for testing deoptimization
1943 void deoptimize();
1944 void make_zombies();
1945
1946 void deoptimize_marked_methods();
1947
1948 public:
1949 // Returns the running thread as a JavaThread
1950 static inline JavaThread* current();
1951
1952 // Returns the active Java thread. Do not use this if you know you are calling
1953 // from a JavaThread, as it's slower than JavaThread::current. If called from
1954 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1955 // operation. You may not want that either.
1956 static JavaThread* active();
1957
1958 inline CompilerThread* as_CompilerThread();
1959
1960 protected:
1961 virtual void pre_run();
1962 virtual void run();
1963 void thread_main_inner();
1964 virtual void post_run();
1965
1966
1967 private:
1968 GrowableArray<oop>* _array_for_gc;
1969 public:
1970
1971 void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1972
1973 public:
1974 // Thread local information maintained by JVMTI.
1975 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1976 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1977 // getter is used to get this JavaThread's JvmtiThreadState if it has
1978 // one which means NULL can be returned. JvmtiThreadState::state_for()
1979 // is used to get the specified JavaThread's JvmtiThreadState if it has
1980 // one or it allocates a new JvmtiThreadState for the JavaThread and
1981 // returns it. JvmtiThreadState::state_for() will return NULL only if
1982 // the specified JavaThread is exiting.
1983 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1984 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1985
1986 // JVMTI PopFrame support
1987 // Setting and clearing popframe_condition
1988 // All of these enumerated values are bits. popframe_pending
1989 // indicates that a PopFrame() has been requested and not yet been
1990 // completed. popframe_processing indicates that that PopFrame() is in
1991 // the process of being completed. popframe_force_deopt_reexecution_bit
1992 // indicates that special handling is required when returning to a
1993 // deoptimized caller.
1994 enum PopCondition {
1995 popframe_inactive = 0x00,
1996 popframe_pending_bit = 0x01,
1997 popframe_processing_bit = 0x02,
1998 popframe_force_deopt_reexecution_bit = 0x04
1999 };
2000 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
2001 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
2002 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
2003 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
2004 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
2005 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
2006 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
2007 void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
2008
2009 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
2010 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
2011 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
2012
2013 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
2014 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
2015 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
2016
2017 private:
2018 // Saved incoming arguments to popped frame.
2019 // Used only when popped interpreted frame returns to deoptimized frame.
2020 void* _popframe_preserved_args;
2021 int _popframe_preserved_args_size;
2022
2023 public:
2024 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
2025 void* popframe_preserved_args();
2026 ByteSize popframe_preserved_args_size();
2027 WordSize popframe_preserved_args_size_in_words();
2028 void popframe_free_preserved_args();
2029
2030
2031 private:
2032 JvmtiThreadState *_jvmti_thread_state;
2033
2034 // Used by the interpreter in fullspeed mode for frame pop, method
2035 // entry, method exit and single stepping support. This field is
2036 // only set to non-zero at a safepoint or using a direct handshake
2037 // (see EnterInterpOnlyModeClosure).
2038 // It can be set to zero asynchronously to this threads execution (i.e., without
2039 // safepoint/handshake or a lock) so we have to be very careful.
2040 // Accesses by other threads are synchronized using JvmtiThreadState_lock though.
2041 int _interp_only_mode;
2042
2043 public:
2044 // used by the interpreter for fullspeed debugging support (see above)
2045 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
2046 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
2047 int get_interp_only_mode() { return _interp_only_mode; }
2048 void increment_interp_only_mode() { ++_interp_only_mode; }
2049 void decrement_interp_only_mode() { --_interp_only_mode; }
2050
2051 // support for cached flag that indicates whether exceptions need to be posted for this thread
2052 // if this is false, we can avoid deoptimizing when events are thrown
2053 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
2054 private:
2055 int _should_post_on_exceptions_flag;
2056
2057 public:
2058 int should_post_on_exceptions_flag() { return _should_post_on_exceptions_flag; }
2059 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
2060
2061 private:
2062 ThreadStatistics *_thread_stat;
2063
2064 public:
2065 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
2066
2067 // Return a blocker object for which this thread is blocked parking.
2068 oop current_park_blocker();
2069
2070 private:
2071 static size_t _stack_size_at_create;
2072
2073 public:
2074 static inline size_t stack_size_at_create(void) {
2075 return _stack_size_at_create;
2076 }
2077 static inline void set_stack_size_at_create(size_t value) {
2078 _stack_size_at_create = value;
2079 }
2080
2081 // Machine dependent stuff
2082 #include OS_CPU_HEADER(thread)
2083
2084 // JSR166 per-thread parker
2085 private:
2086 Parker* _parker;
2087 public:
2088 Parker* parker() { return _parker; }
2089
2090 // Biased locking support
2091 private:
2092 GrowableArray<MonitorInfo*>* _cached_monitor_info;
2093 public:
2094 GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
2095 void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
2096
2097 // clearing/querying jni attach status
2098 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
2099 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
2100 inline void set_done_attaching_via_jni();
2101
2102 // Stack dump assistance:
2103 // Track the class we want to initialize but for which we have to wait
2104 // on its init_lock() because it is already being initialized.
2105 void set_class_to_be_initialized(InstanceKlass* k);
2106 InstanceKlass* class_to_be_initialized() const;
2107
2108 private:
2109 InstanceKlass* _class_to_be_initialized;
2110
2111 // java.lang.Thread.sleep support
2112 ParkEvent * _SleepEvent;
2113 public:
2114 bool sleep(jlong millis);
2115
2116 // java.lang.Thread interruption support
2117 void interrupt();
2118 bool is_interrupted(bool clear_interrupted);
2119
2120 };
2121
2122 // Inline implementation of JavaThread::current
2123 inline JavaThread* JavaThread::current() {
2124 Thread* thread = Thread::current();
2125 assert(thread->is_Java_thread(), "just checking");
2126 return (JavaThread*)thread;
2127 }
2128
2129 inline CompilerThread* JavaThread::as_CompilerThread() {
2130 assert(is_Compiler_thread(), "just checking");
2131 return (CompilerThread*)this;
2132 }
2133
2134 // Dedicated thread to sweep the code cache
2135 class CodeCacheSweeperThread : public JavaThread {
2136 CompiledMethod* _scanned_compiled_method; // nmethod being scanned by the sweeper
2137 public:
2138 CodeCacheSweeperThread();
2139 // Track the nmethod currently being scanned by the sweeper
2140 void set_scanned_compiled_method(CompiledMethod* cm) {
2141 assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value");
2142 _scanned_compiled_method = cm;
2143 }
2144
2145 // Hide sweeper thread from external view.
2146 bool is_hidden_from_external_view() const { return true; }
2147
2148 bool is_Code_cache_sweeper_thread() const { return true; }
2149
2150 // Prevent GC from unloading _scanned_compiled_method
2151 void oops_do(OopClosure* f, CodeBlobClosure* cf);
2152 void nmethods_do(CodeBlobClosure* cf);
2153 };
2154
2155 // A thread used for Compilation.
2156 class CompilerThread : public JavaThread {
2157 friend class VMStructs;
2158 private:
2159 CompilerCounters* _counters;
2160
2161 ciEnv* _env;
2162 CompileLog* _log;
2163 CompileTask* volatile _task; // print_threads_compiling can read this concurrently.
2164 CompileQueue* _queue;
2165 BufferBlob* _buffer_blob;
2166
2167 AbstractCompiler* _compiler;
2168 TimeStamp _idle_time;
2169
2170 public:
2171
2172 static CompilerThread* current();
2173
2174 CompilerThread(CompileQueue* queue, CompilerCounters* counters);
2175 ~CompilerThread();
2176
2177 bool is_Compiler_thread() const { return true; }
2178
2179 virtual bool can_call_java() const;
2180
2181 // Hide native compiler threads from external view.
2182 bool is_hidden_from_external_view() const { return !can_call_java(); }
2183
2184 void set_compiler(AbstractCompiler* c) { _compiler = c; }
2185 AbstractCompiler* compiler() const { return _compiler; }
2186
2187 CompileQueue* queue() const { return _queue; }
2188 CompilerCounters* counters() const { return _counters; }
2189
2190 // Get/set the thread's compilation environment.
2191 ciEnv* env() { return _env; }
2192 void set_env(ciEnv* env) { _env = env; }
2193
2194 BufferBlob* get_buffer_blob() const { return _buffer_blob; }
2195 void set_buffer_blob(BufferBlob* b) { _buffer_blob = b; }
2196
2197 // Get/set the thread's logging information
2198 CompileLog* log() { return _log; }
2199 void init_log(CompileLog* log) {
2200 // Set once, for good.
2201 assert(_log == NULL, "set only once");
2202 _log = log;
2203 }
2204
2205 void start_idle_timer() { _idle_time.update(); }
2206 jlong idle_time_millis() {
2207 return TimeHelper::counter_to_millis(_idle_time.ticks_since_update());
2208 }
2209
2210 #ifndef PRODUCT
2211 private:
2212 IdealGraphPrinter *_ideal_graph_printer;
2213 public:
2214 IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; }
2215 void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2216 #endif
2217
2218 // Get/set the thread's current task
2219 CompileTask* task() { return _task; }
2220 void set_task(CompileTask* task) { _task = task; }
2221 };
2222
2223 inline CompilerThread* CompilerThread::current() {
2224 return JavaThread::current()->as_CompilerThread();
2225 }
2226
2227 // The active thread queue. It also keeps track of the current used
2228 // thread priorities.
2229 class Threads: AllStatic {
2230 friend class VMStructs;
2231 private:
2232 static int _number_of_threads;
2233 static int _number_of_non_daemon_threads;
2234 static int _return_code;
2235 static uintx _thread_claim_token;
2236 #ifdef ASSERT
2237 static bool _vm_complete;
2238 #endif
2239
2240 static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2241 static void initialize_jsr292_core_classes(TRAPS);
2242
2243 public:
2244 // Thread management
2245 // force_daemon is a concession to JNI, where we may need to add a
2246 // thread to the thread list before allocating its thread object
2247 static void add(JavaThread* p, bool force_daemon = false);
2248 static void remove(JavaThread* p, bool is_daemon);
2249 static void non_java_threads_do(ThreadClosure* tc);
2250 static void java_threads_do(ThreadClosure* tc);
2251 static void java_threads_and_vm_thread_do(ThreadClosure* tc);
2252 static void threads_do(ThreadClosure* tc);
2253 static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
2254
2255 // Initializes the vm and creates the vm thread
2256 static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
2257 static void convert_vm_init_libraries_to_agents();
2258 static void create_vm_init_libraries();
2259 static void create_vm_init_agents();
2260 static void shutdown_vm_agents();
2261 static bool destroy_vm();
2262 // Supported VM versions via JNI
2263 // Includes JNI_VERSION_1_1
2264 static jboolean is_supported_jni_version_including_1_1(jint version);
2265 // Does not include JNI_VERSION_1_1
2266 static jboolean is_supported_jni_version(jint version);
2267
2268 // The "thread claim token" provides a way for threads to be claimed
2269 // by parallel worker tasks.
2270 //
2271 // Each thread contains a "token" field. A task will claim the
2272 // thread only if its token is different from the global token,
2273 // which is updated by calling change_thread_claim_token(). When
2274 // a thread is claimed, it's token is set to the global token value
2275 // so other threads in the same iteration pass won't claim it.
2276 //
2277 // For this to work change_thread_claim_token() needs to be called
2278 // exactly once in sequential code before starting parallel tasks
2279 // that should claim threads.
2280 //
2281 // New threads get their token set to 0 and change_thread_claim_token()
2282 // never sets the global token to 0.
2283 static uintx thread_claim_token() { return _thread_claim_token; }
2284 static void change_thread_claim_token();
2285 static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
2286
2287 // Apply "f->do_oop" to all root oops in all threads.
2288 // This version may only be called by sequential code.
2289 static void oops_do(OopClosure* f, CodeBlobClosure* cf);
2290 // This version may be called by sequential or parallel code.
2291 static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
2292
2293 // Sweeper
2294 static void nmethods_do(CodeBlobClosure* cf);
2295
2296 // RedefineClasses support
2297 static void metadata_do(MetadataClosure* f);
2298 static void metadata_handles_do(void f(Metadata*));
2299
2300 #ifdef ASSERT
2301 static bool is_vm_complete() { return _vm_complete; }
2302 #endif // ASSERT
2303
2304 // Verification
2305 static void verify();
2306 static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks, bool print_extended_info);
2307 static void print(bool print_stacks, bool internal_format) {
2308 // this function is only used by debug.cpp
2309 print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */, false /* simple format */);
2310 }
2311 static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2312 static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
2313 int buflen, bool* found_current);
2314 static void print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form = false);
2315
2316 // Get Java threads that are waiting to enter a monitor.
2317 static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
2318 int count, address monitor);
2319
2320 // Get owning Java thread from the monitor's owner field.
2321 static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
2322 address owner);
2323
2324 // Number of threads on the active threads list
2325 static int number_of_threads() { return _number_of_threads; }
2326 // Number of non-daemon threads on the active threads list
2327 static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; }
2328
2329 // Deoptimizes all frames tied to marked nmethods
2330 static void deoptimized_wrt_marked_nmethods();
2331
2332 struct Test; // For private gtest access.
2333 };
2334
2335 class SignalHandlerMark: public StackObj {
2336 private:
2337 Thread* _thread;
2338 public:
2339 SignalHandlerMark(Thread* t) {
2340 _thread = t;
2341 if (_thread) _thread->enter_signal_handler();
2342 }
2343 ~SignalHandlerMark() {
2344 if (_thread) _thread->leave_signal_handler();
2345 _thread = NULL;
2346 }
2347 };
2348
2349
2350 #endif // SHARE_RUNTIME_THREAD_HPP