94 // [Debugging information]
95 // - oop array
96 // - data array
97 // - pcs
98 // [Exception handler table]
99 // - handler entry point array
100 // [Implicit Null Pointer exception table]
101 // - implicit null table array
102
103 class Dependencies;
104 class ExceptionHandlerTable;
105 class ImplicitExceptionTable;
106 class AbstractCompiler;
107 class xmlStream;
108
109 class nmethod : public CodeBlob {
110 friend class VMStructs;
111 friend class NMethodSweeper;
112 friend class CodeCache; // scavengable oops
113 private:
114 // Shared fields for all nmethod's
115 Method* _method;
116 int _entry_bci; // != InvocationEntryBci if this nmethod is an on-stack replacement method
117 jmethodID _jmethod_id; // Cache of method()->jmethod_id()
118
119 // To support simple linked-list chaining of nmethods:
120 nmethod* _osr_link; // from InstanceKlass::osr_nmethods_head
121 nmethod* _scavenge_root_link; // from CodeCache::scavenge_root_nmethods
122
123 static nmethod* volatile _oops_do_mark_nmethods;
124 nmethod* volatile _oops_do_mark_link;
125
126 AbstractCompiler* _compiler; // The compiler which compiled this nmethod
127
128 // offsets for entry points
129 address _entry_point; // entry point with class check
130 address _verified_entry_point; // entry point without class check
131 address _osr_entry_point; // entry point for on stack replacement
132
133 // Offsets for different nmethod parts
134 int _exception_offset;
135 // All deoptee's will resume execution at this location described by
136 // this offset.
137 int _deoptimize_offset;
138 // All deoptee's at a MethodHandle call site will resume execution
139 // at this location described by this offset.
140 int _deoptimize_mh_offset;
141 // Offset of the unwind handler if it exists
163 int _comp_level; // compilation level
164
165 // protected by CodeCache_lock
166 bool _has_flushed_dependencies; // Used for maintenance of dependencies (CodeCache_lock)
167
168 bool _marked_for_reclamation; // Used by NMethodSweeper (set only by sweeper)
169 bool _marked_for_deoptimization; // Used for stack deoptimization
170
171 // used by jvmti to track if an unload event has been posted for this nmethod.
172 bool _unload_reported;
173
174 // set during construction
175 unsigned int _has_unsafe_access:1; // May fault due to unsafe access.
176 unsigned int _has_method_handle_invokes:1; // Has this method MethodHandle invokes?
177 unsigned int _lazy_critical_native:1; // Lazy JNI critical native
178 unsigned int _has_wide_vectors:1; // Preserve wide vectors at safepoints
179
180 // Protected by Patching_lock
181 volatile unsigned char _state; // {alive, not_entrant, zombie, unloaded}
182
183 #ifdef ASSERT
184 bool _oops_are_stale; // indicates that it's no longer safe to access oops section
185 #endif
186
187 enum { in_use = 0, // executable nmethod
188 not_entrant = 1, // marked for deoptimization but activations may still exist,
189 // will be transformed to zombie when all activations are gone
190 zombie = 2, // no activations exist, nmethod is ready for purge
191 unloaded = 3 }; // there should be no activations, should not be called,
192 // will be transformed to zombie immediately
193
194 jbyte _scavenge_root_state;
195
196 #if INCLUDE_RTM_OPT
197 // RTM state at compile time. Used during deoptimization to decide
198 // whether to restart collecting RTM locking abort statistic again.
199 RTMState _rtm_state;
200 #endif
201
202 // Nmethod Flushing lock. If non-zero, then the nmethod is not removed
420 bool is_zombie() const { return _state == zombie; }
421 bool is_unloaded() const { return _state == unloaded; }
422
423 #if INCLUDE_RTM_OPT
424 // rtm state accessing and manipulating
425 RTMState rtm_state() const { return _rtm_state; }
426 void set_rtm_state(RTMState state) { _rtm_state = state; }
427 #endif
428
429 // Make the nmethod non entrant. The nmethod will continue to be
430 // alive. It is used when an uncommon trap happens. Returns true
431 // if this thread changed the state of the nmethod or false if
432 // another thread performed the transition.
433 bool make_not_entrant() { return make_not_entrant_or_zombie(not_entrant); }
434 bool make_zombie() { return make_not_entrant_or_zombie(zombie); }
435
436 // used by jvmti to track if the unload event has been reported
437 bool unload_reported() { return _unload_reported; }
438 void set_unload_reported() { _unload_reported = true; }
439
440 bool is_marked_for_deoptimization() const { return _marked_for_deoptimization; }
441 void mark_for_deoptimization() { _marked_for_deoptimization = true; }
442
443 void make_unloaded(BoolObjectClosure* is_alive, oop cause);
444
445 bool has_dependencies() { return dependencies_size() != 0; }
446 void flush_dependencies(BoolObjectClosure* is_alive);
447 bool has_flushed_dependencies() { return _has_flushed_dependencies; }
448 void set_has_flushed_dependencies() {
449 assert(!has_flushed_dependencies(), "should only happen once");
450 _has_flushed_dependencies = 1;
451 }
452
453 bool is_marked_for_reclamation() const { return _marked_for_reclamation; }
454 void mark_for_reclamation() { _marked_for_reclamation = 1; }
455
456 bool has_unsafe_access() const { return _has_unsafe_access; }
457 void set_has_unsafe_access(bool z) { _has_unsafe_access = z; }
458
459 bool has_method_handle_invokes() const { return _has_method_handle_invokes; }
535 address continuation_for_implicit_exception(address pc);
536
537 // On-stack replacement support
538 int osr_entry_bci() const { assert(is_osr_method(), "wrong kind of nmethod"); return _entry_bci; }
539 address osr_entry() const { assert(is_osr_method(), "wrong kind of nmethod"); return _osr_entry_point; }
540 void invalidate_osr_method();
541 nmethod* osr_link() const { return _osr_link; }
542 void set_osr_link(nmethod *n) { _osr_link = n; }
543
544 // tells whether frames described by this nmethod can be deoptimized
545 // note: native wrappers cannot be deoptimized.
546 bool can_be_deoptimized() const { return is_java_method(); }
547
548 // Inline cache support
549 void clear_inline_caches();
550 void cleanup_inline_caches();
551 bool inlinecache_check_contains(address addr) const {
552 return (addr >= code_begin() && addr < verified_entry_point());
553 }
554
555 // Check that all metadata is still alive
556 void verify_metadata_loaders(address low_boundary, BoolObjectClosure* is_alive);
557
558 // unlink and deallocate this nmethod
559 // Only NMethodSweeper class is expected to use this. NMethodSweeper is not
560 // expected to use any other private methods/data in this class.
561
562 protected:
563 void flush();
564
565 public:
566 // When true is returned, it is unsafe to remove this nmethod even if
567 // it is a zombie, since the VM or the ServiceThread might still be
568 // using it.
569 bool is_locked_by_vm() const { return _lock_count >0; }
570
571 // See comment at definition of _last_seen_on_stack
572 void mark_as_seen_on_stack();
573 bool can_not_entrant_be_converted();
574
575 // Evolution support. We make old (discarded) compiled methods point to new Method*s.
576 void set_method(Method* method) { _method = method; }
577
578 // GC support
579 void do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred);
580 bool can_unload(BoolObjectClosure* is_alive, oop* root, bool unloading_occurred);
581
582 void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map,
583 OopClosure* f);
584 void oops_do(OopClosure* f) { oops_do(f, false); }
585 void oops_do(OopClosure* f, bool allow_zombie);
586 bool detect_scavenge_root_oops();
587 void verify_scavenge_root_oops() PRODUCT_RETURN;
588
589 bool test_set_oops_do_mark();
590 static void oops_do_marking_prologue();
591 static void oops_do_marking_epilogue();
592 static bool oops_do_marking_is_active() { return _oops_do_mark_nmethods != NULL; }
593 bool test_oops_do_mark() { return _oops_do_mark_link != NULL; }
594
595 // ScopeDesc for an instruction
596 ScopeDesc* scope_desc_at(address pc);
597
598 private:
599 ScopeDesc* scope_desc_in(address begin, address end);
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94 // [Debugging information]
95 // - oop array
96 // - data array
97 // - pcs
98 // [Exception handler table]
99 // - handler entry point array
100 // [Implicit Null Pointer exception table]
101 // - implicit null table array
102
103 class Dependencies;
104 class ExceptionHandlerTable;
105 class ImplicitExceptionTable;
106 class AbstractCompiler;
107 class xmlStream;
108
109 class nmethod : public CodeBlob {
110 friend class VMStructs;
111 friend class NMethodSweeper;
112 friend class CodeCache; // scavengable oops
113 private:
114
115 // GC support to help figure out if an nmethod has been
116 // cleaned/unloaded by the current GC.
117 static unsigned char _global_unloading_clock;
118
119 // Shared fields for all nmethod's
120 Method* _method;
121 int _entry_bci; // != InvocationEntryBci if this nmethod is an on-stack replacement method
122 jmethodID _jmethod_id; // Cache of method()->jmethod_id()
123
124 // To support simple linked-list chaining of nmethods:
125 nmethod* _osr_link; // from InstanceKlass::osr_nmethods_head
126
127 union {
128 // Used by G1 to chain nmethods.
129 nmethod* _unloading_next;
130 // Used by non-G1 GCs to chain nmethods.
131 nmethod* _scavenge_root_link; // from CodeCache::scavenge_root_nmethods
132 };
133
134 static nmethod* volatile _oops_do_mark_nmethods;
135 nmethod* volatile _oops_do_mark_link;
136
137 AbstractCompiler* _compiler; // The compiler which compiled this nmethod
138
139 // offsets for entry points
140 address _entry_point; // entry point with class check
141 address _verified_entry_point; // entry point without class check
142 address _osr_entry_point; // entry point for on stack replacement
143
144 // Offsets for different nmethod parts
145 int _exception_offset;
146 // All deoptee's will resume execution at this location described by
147 // this offset.
148 int _deoptimize_offset;
149 // All deoptee's at a MethodHandle call site will resume execution
150 // at this location described by this offset.
151 int _deoptimize_mh_offset;
152 // Offset of the unwind handler if it exists
174 int _comp_level; // compilation level
175
176 // protected by CodeCache_lock
177 bool _has_flushed_dependencies; // Used for maintenance of dependencies (CodeCache_lock)
178
179 bool _marked_for_reclamation; // Used by NMethodSweeper (set only by sweeper)
180 bool _marked_for_deoptimization; // Used for stack deoptimization
181
182 // used by jvmti to track if an unload event has been posted for this nmethod.
183 bool _unload_reported;
184
185 // set during construction
186 unsigned int _has_unsafe_access:1; // May fault due to unsafe access.
187 unsigned int _has_method_handle_invokes:1; // Has this method MethodHandle invokes?
188 unsigned int _lazy_critical_native:1; // Lazy JNI critical native
189 unsigned int _has_wide_vectors:1; // Preserve wide vectors at safepoints
190
191 // Protected by Patching_lock
192 volatile unsigned char _state; // {alive, not_entrant, zombie, unloaded}
193
194 volatile unsigned char _unloading_clock; // Incremented after GC unloaded/cleaned the nmethod
195
196 #ifdef ASSERT
197 bool _oops_are_stale; // indicates that it's no longer safe to access oops section
198 #endif
199
200 enum { in_use = 0, // executable nmethod
201 not_entrant = 1, // marked for deoptimization but activations may still exist,
202 // will be transformed to zombie when all activations are gone
203 zombie = 2, // no activations exist, nmethod is ready for purge
204 unloaded = 3 }; // there should be no activations, should not be called,
205 // will be transformed to zombie immediately
206
207 jbyte _scavenge_root_state;
208
209 #if INCLUDE_RTM_OPT
210 // RTM state at compile time. Used during deoptimization to decide
211 // whether to restart collecting RTM locking abort statistic again.
212 RTMState _rtm_state;
213 #endif
214
215 // Nmethod Flushing lock. If non-zero, then the nmethod is not removed
433 bool is_zombie() const { return _state == zombie; }
434 bool is_unloaded() const { return _state == unloaded; }
435
436 #if INCLUDE_RTM_OPT
437 // rtm state accessing and manipulating
438 RTMState rtm_state() const { return _rtm_state; }
439 void set_rtm_state(RTMState state) { _rtm_state = state; }
440 #endif
441
442 // Make the nmethod non entrant. The nmethod will continue to be
443 // alive. It is used when an uncommon trap happens. Returns true
444 // if this thread changed the state of the nmethod or false if
445 // another thread performed the transition.
446 bool make_not_entrant() { return make_not_entrant_or_zombie(not_entrant); }
447 bool make_zombie() { return make_not_entrant_or_zombie(zombie); }
448
449 // used by jvmti to track if the unload event has been reported
450 bool unload_reported() { return _unload_reported; }
451 void set_unload_reported() { _unload_reported = true; }
452
453 void set_unloading_next(nmethod* next) { _unloading_next = next; }
454 nmethod* unloading_next() { return _unloading_next; }
455
456 static unsigned char global_unloading_clock() { return _global_unloading_clock; }
457 static void increase_unloading_clock();
458
459 void set_unloading_clock(unsigned char unloading_clock);
460 unsigned char unloading_clock();
461
462 bool is_marked_for_deoptimization() const { return _marked_for_deoptimization; }
463 void mark_for_deoptimization() { _marked_for_deoptimization = true; }
464
465 void make_unloaded(BoolObjectClosure* is_alive, oop cause);
466
467 bool has_dependencies() { return dependencies_size() != 0; }
468 void flush_dependencies(BoolObjectClosure* is_alive);
469 bool has_flushed_dependencies() { return _has_flushed_dependencies; }
470 void set_has_flushed_dependencies() {
471 assert(!has_flushed_dependencies(), "should only happen once");
472 _has_flushed_dependencies = 1;
473 }
474
475 bool is_marked_for_reclamation() const { return _marked_for_reclamation; }
476 void mark_for_reclamation() { _marked_for_reclamation = 1; }
477
478 bool has_unsafe_access() const { return _has_unsafe_access; }
479 void set_has_unsafe_access(bool z) { _has_unsafe_access = z; }
480
481 bool has_method_handle_invokes() const { return _has_method_handle_invokes; }
557 address continuation_for_implicit_exception(address pc);
558
559 // On-stack replacement support
560 int osr_entry_bci() const { assert(is_osr_method(), "wrong kind of nmethod"); return _entry_bci; }
561 address osr_entry() const { assert(is_osr_method(), "wrong kind of nmethod"); return _osr_entry_point; }
562 void invalidate_osr_method();
563 nmethod* osr_link() const { return _osr_link; }
564 void set_osr_link(nmethod *n) { _osr_link = n; }
565
566 // tells whether frames described by this nmethod can be deoptimized
567 // note: native wrappers cannot be deoptimized.
568 bool can_be_deoptimized() const { return is_java_method(); }
569
570 // Inline cache support
571 void clear_inline_caches();
572 void cleanup_inline_caches();
573 bool inlinecache_check_contains(address addr) const {
574 return (addr >= code_begin() && addr < verified_entry_point());
575 }
576
577 // Verify calls to dead methods have been cleaned.
578 void verify_clean_inline_caches();
579 // Verify and count cached icholder relocations.
580 int verify_icholder_relocations();
581 // Check that all metadata is still alive
582 void verify_metadata_loaders(address low_boundary, BoolObjectClosure* is_alive);
583
584 // unlink and deallocate this nmethod
585 // Only NMethodSweeper class is expected to use this. NMethodSweeper is not
586 // expected to use any other private methods/data in this class.
587
588 protected:
589 void flush();
590
591 public:
592 // When true is returned, it is unsafe to remove this nmethod even if
593 // it is a zombie, since the VM or the ServiceThread might still be
594 // using it.
595 bool is_locked_by_vm() const { return _lock_count >0; }
596
597 // See comment at definition of _last_seen_on_stack
598 void mark_as_seen_on_stack();
599 bool can_not_entrant_be_converted();
600
601 // Evolution support. We make old (discarded) compiled methods point to new Method*s.
602 void set_method(Method* method) { _method = method; }
603
604 // GC support
605 void do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred);
606 // The parallel versions are used by G1.
607 bool do_unloading_parallel(BoolObjectClosure* is_alive, bool unloading_occurred);
608 void do_unloading_parallel_postponed(BoolObjectClosure* is_alive, bool unloading_occurred);
609 // Unload a nmethod if the *root object is dead.
610 bool can_unload(BoolObjectClosure* is_alive, oop* root, bool unloading_occurred);
611
612 void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map,
613 OopClosure* f);
614 void oops_do(OopClosure* f) { oops_do(f, false); }
615 void oops_do(OopClosure* f, bool allow_zombie);
616 bool detect_scavenge_root_oops();
617 void verify_scavenge_root_oops() PRODUCT_RETURN;
618
619 bool test_set_oops_do_mark();
620 static void oops_do_marking_prologue();
621 static void oops_do_marking_epilogue();
622 static bool oops_do_marking_is_active() { return _oops_do_mark_nmethods != NULL; }
623 bool test_oops_do_mark() { return _oops_do_mark_link != NULL; }
624
625 // ScopeDesc for an instruction
626 ScopeDesc* scope_desc_at(address pc);
627
628 private:
629 ScopeDesc* scope_desc_in(address begin, address end);
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