71 // VtableStubs creates the code stubs for compiled calls through vtables.
72 // There is one stub per (vtable index, args_size) pair, and the stubs are
73 // never deallocated. They don't need to be GCed because they contain no oops.
74 class VtableStub;
75
76 class VtableStubs : AllStatic {
77 public: // N must be public (some compilers need this for _table)
78 enum {
79 N = 256, // size of stub table; must be power of two
80 mask = N - 1
81 };
82
83 static_assert(is_power_of_2((int)N), "N must be a power of 2");
84
85 private:
86 friend class VtableStub;
87 static VtableStub* volatile _table[N]; // table of existing stubs
88 static int _vtab_stub_size; // current size estimate for vtable stub (quasi-constant)
89 static int _itab_stub_size; // current size estimate for itable stub (quasi-constant)
90
91 static VtableStub* create_vtable_stub(int vtable_index);
92 static VtableStub* create_itable_stub(int vtable_index);
93 static VtableStub* lookup (bool is_vtable_stub, int vtable_index);
94 static void enter (bool is_vtable_stub, int vtable_index, VtableStub* s);
95 static inline uint hash (bool is_vtable_stub, int vtable_index);
96 static address find_stub (bool is_vtable_stub, int vtable_index);
97 static void bookkeeping(MacroAssembler* masm, outputStream* out, VtableStub* s,
98 address npe_addr, address ame_addr, bool is_vtable_stub,
99 int index, int slop_bytes, int index_dependent_slop);
100 static int code_size_limit(bool is_vtable_stub);
101 static void check_and_set_size_limit(bool is_vtable_stub,
102 int code_size,
103 int padding);
104
105 public:
106 static address find_vtable_stub(int vtable_index) { return find_stub(true, vtable_index); }
107 static address find_itable_stub(int itable_index) { return find_stub(false, itable_index); }
108
109 static VtableStub* entry_point(address pc); // vtable stub entry point for a pc
110 static bool contains(address pc); // is pc within any stub?
111 static VtableStub* stub_containing(address pc); // stub containing pc or nullptr
112 static void initialize();
113 static void vtable_stub_do(void f(VtableStub*)); // iterates over all vtable stubs
114 };
115
116
117 class VtableStub {
118 private:
119 friend class VtableStubs;
120
121 static address _chunk; // For allocation
122 static address _chunk_end; // For allocation
123 static VMReg _receiver_location; // Where to find receiver
124
125 VtableStub* _next; // Pointer to next entry in hash table
126 const short _index; // vtable index
127 short _ame_offset; // Where an AbstractMethodError might occur
128 short _npe_offset; // Where a NullPointerException might occur
129 bool _is_vtable_stub; // True if vtable stub, false, is itable stub
130 /* code follows here */ // The vtableStub code
131
132 void* operator new(size_t size, int code_size) throw();
133
134 VtableStub(bool is_vtable_stub, short index)
135 : _next(nullptr), _index(index), _ame_offset(-1), _npe_offset(-1),
136 _is_vtable_stub(is_vtable_stub) {}
137 VtableStub* next() const { return _next; }
138 int index() const { return _index; }
139 static VMReg receiver_location() { return _receiver_location; }
140 void set_next(VtableStub* n) { _next = n; }
141
142 public:
143 address code_begin() const { return (address)(this + 1); }
144 address code_end() const { return code_begin() + VtableStubs::code_size_limit(_is_vtable_stub); }
145 address entry_point() const { return code_begin(); }
146 static int entry_offset() { return sizeof(class VtableStub); }
147
148 bool matches(bool is_vtable_stub, int index) const {
149 return _index == index && _is_vtable_stub == is_vtable_stub;
150 }
151 bool contains(address pc) const { return code_begin() <= pc && pc < code_end(); }
152
153 private:
154 void set_exception_points(address npe_addr, address ame_addr) {
155 _npe_offset = checked_cast<short>(npe_addr - code_begin());
156 _ame_offset = checked_cast<short>(ame_addr - code_begin());
157 assert(is_abstract_method_error(ame_addr), "offset must be correct");
158 assert(is_null_pointer_exception(npe_addr), "offset must be correct");
159 assert(!is_abstract_method_error(npe_addr), "offset must be correct");
160 assert(!is_null_pointer_exception(ame_addr), "offset must be correct");
161 }
162
163 // platform-dependent routines
164 static int pd_code_alignment();
165 // CNC: Removed because vtable stubs are now made with an ideal graph
166 // static bool pd_disregard_arg_size();
167
168 static void align_chunk() {
169 uintptr_t off = (uintptr_t)( _chunk + sizeof(VtableStub) ) % pd_code_alignment();
170 if (off != 0) _chunk += pd_code_alignment() - off;
171 }
172
173 public:
174 // Query
175 bool is_itable_stub() { return !_is_vtable_stub; }
176 bool is_vtable_stub() { return _is_vtable_stub; }
177 bool is_abstract_method_error(address epc) { return epc == code_begin()+_ame_offset; }
178 bool is_null_pointer_exception(address epc) { return epc == code_begin()+_npe_offset; }
179
180 void print_on(outputStream* st) const;
181 void print() const;
182
183 };
184
185 #endif // SHARE_CODE_VTABLESTUBS_HPP
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71 // VtableStubs creates the code stubs for compiled calls through vtables.
72 // There is one stub per (vtable index, args_size) pair, and the stubs are
73 // never deallocated. They don't need to be GCed because they contain no oops.
74 class VtableStub;
75
76 class VtableStubs : AllStatic {
77 public: // N must be public (some compilers need this for _table)
78 enum {
79 N = 256, // size of stub table; must be power of two
80 mask = N - 1
81 };
82
83 static_assert(is_power_of_2((int)N), "N must be a power of 2");
84
85 private:
86 friend class VtableStub;
87 static VtableStub* volatile _table[N]; // table of existing stubs
88 static int _vtab_stub_size; // current size estimate for vtable stub (quasi-constant)
89 static int _itab_stub_size; // current size estimate for itable stub (quasi-constant)
90
91 static VtableStub* create_vtable_stub(int vtable_index, bool caller_is_c1);
92 static VtableStub* create_itable_stub(int vtable_index, bool caller_is_c1);
93 static VtableStub* lookup (bool is_vtable_stub, int vtable_index, bool caller_is_c1);
94 static void enter (bool is_vtable_stub, int vtable_index, bool caller_is_c1, VtableStub* s);
95 static inline uint hash (bool is_vtable_stub, int vtable_index, bool caller_is_c1);
96 static address find_stub (bool is_vtable_stub, int vtable_index, bool caller_is_c1);
97 static void bookkeeping(MacroAssembler* masm, outputStream* out, VtableStub* s,
98 address npe_addr, address ame_addr, bool is_vtable_stub,
99 int index, int slop_bytes, int index_dependent_slop);
100 static int code_size_limit(bool is_vtable_stub);
101 static void check_and_set_size_limit(bool is_vtable_stub,
102 int code_size,
103 int padding);
104
105 public:
106 static address find_vtable_stub(int vtable_index, bool caller_is_c1) { return find_stub(true, vtable_index, caller_is_c1); }
107 static address find_itable_stub(int itable_index, bool caller_is_c1) { return find_stub(false, itable_index, caller_is_c1); }
108
109 static VtableStub* entry_point(address pc); // vtable stub entry point for a pc
110 static bool contains(address pc); // is pc within any stub?
111 static VtableStub* stub_containing(address pc); // stub containing pc or nullptr
112 static void initialize();
113 static void vtable_stub_do(void f(VtableStub*)); // iterates over all vtable stubs
114 };
115
116
117 class VtableStub {
118 private:
119 friend class VtableStubs;
120
121 static address _chunk; // For allocation
122 static address _chunk_end; // For allocation
123 static VMReg _receiver_location; // Where to find receiver
124
125 VtableStub* _next; // Pointer to next entry in hash table
126 const short _index; // vtable index
127 short _ame_offset; // Where an AbstractMethodError might occur
128 short _npe_offset; // Where a NullPointerException might occur
129 bool _is_vtable_stub; // True if vtable stub, false, is itable stub
130 bool _caller_is_c1; // True if this is for a caller compiled by C1,
131 // which doesn't scalarize parameters.
132 /* code follows here */ // The vtableStub code
133
134 void* operator new(size_t size, int code_size) throw();
135
136 VtableStub(bool is_vtable_stub, short index, bool caller_is_c1)
137 : _next(nullptr), _index(index), _ame_offset(-1), _npe_offset(-1),
138 _is_vtable_stub(is_vtable_stub), _caller_is_c1(caller_is_c1) {}
139 VtableStub* next() const { return _next; }
140 int index() const { return _index; }
141 static VMReg receiver_location() { return _receiver_location; }
142 void set_next(VtableStub* n) { _next = n; }
143
144 public:
145 address code_begin() const { return (address)(this + 1); }
146 address code_end() const { return code_begin() + VtableStubs::code_size_limit(_is_vtable_stub); }
147 address entry_point() const { return code_begin(); }
148 static int entry_offset() { return sizeof(class VtableStub); }
149
150 bool matches(bool is_vtable_stub, int index, bool caller_is_c1) const {
151 return _index == index && _is_vtable_stub == is_vtable_stub && _caller_is_c1 == caller_is_c1;
152 }
153 bool contains(address pc) const { return code_begin() <= pc && pc < code_end(); }
154
155 private:
156 void set_exception_points(address npe_addr, address ame_addr) {
157 _npe_offset = checked_cast<short>(npe_addr - code_begin());
158 _ame_offset = checked_cast<short>(ame_addr - code_begin());
159 assert(is_abstract_method_error(ame_addr), "offset must be correct");
160 assert(is_null_pointer_exception(npe_addr), "offset must be correct");
161 assert(!is_abstract_method_error(npe_addr), "offset must be correct");
162 assert(!is_null_pointer_exception(ame_addr), "offset must be correct");
163 }
164
165 // platform-dependent routines
166 static int pd_code_alignment();
167 // CNC: Removed because vtable stubs are now made with an ideal graph
168 // static bool pd_disregard_arg_size();
169
170 static void align_chunk() {
171 uintptr_t off = (uintptr_t)( _chunk + sizeof(VtableStub) ) % pd_code_alignment();
172 if (off != 0) _chunk += pd_code_alignment() - off;
173 }
174
175 public:
176 // Query
177 bool is_itable_stub() { return !_is_vtable_stub; }
178 bool is_vtable_stub() { return _is_vtable_stub; }
179 bool caller_is_c1() { return _caller_is_c1; }
180 bool is_abstract_method_error(address epc) { return epc == code_begin()+_ame_offset; }
181 bool is_null_pointer_exception(address epc) { return epc == code_begin()+_npe_offset; }
182
183 void print_on(outputStream* st) const;
184 void print() const;
185
186 };
187
188 #endif // SHARE_CODE_VTABLESTUBS_HPP
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