73 void* res = _chunk;
74 _chunk += real_size;
75 align_chunk();
76 return res;
77 }
78
79
80 void VtableStub::print_on(outputStream* st) const {
81 st->print("vtable stub (index = %d, receiver_location = " INTX_FORMAT ", code = [" INTPTR_FORMAT ", " INTPTR_FORMAT "[)",
82 index(), p2i(receiver_location()), p2i(code_begin()), p2i(code_end()));
83 }
84
85
86 // -----------------------------------------------------------------------------------------
87 // Implementation of VtableStubs
88 //
89 // For each hash value there's a linked list of vtable stubs (with that
90 // hash value). Each list is anchored in a little hash _table, indexed
91 // by that hash value.
92
93 VtableStub* VtableStubs::_table[VtableStubs::N];
94 int VtableStubs::_number_of_vtable_stubs = 0;
95
96
97 void VtableStubs::initialize() {
98 VtableStub::_receiver_location = SharedRuntime::name_for_receiver();
99 {
100 MutexLocker ml(VtableStubs_lock);
101 assert(_number_of_vtable_stubs == 0, "potential performance bug: VtableStubs initialized more than once");
102 assert(is_power_of_2(N), "N must be a power of 2");
103 for (int i = 0; i < N; i++) {
104 _table[i] = NULL;
105 }
106 }
107 }
108
109
110 address VtableStubs::find_stub(bool is_vtable_stub, int vtable_index) {
111 assert(vtable_index >= 0, "must be positive");
112
113 VtableStub* s = ShareVtableStubs ? lookup(is_vtable_stub, vtable_index) : NULL;
114 if (s == NULL) {
115 if (is_vtable_stub) {
116 s = create_vtable_stub(vtable_index);
117 } else {
118 s = create_itable_stub(vtable_index);
119 }
120
121 // Creation of vtable or itable can fail if there is not enough free space in the code cache.
122 if (s == NULL) {
123 return NULL;
124 }
125
126 enter(is_vtable_stub, vtable_index, s);
127 if (PrintAdapterHandlers) {
128 tty->print_cr("Decoding VtableStub %s[%d]@" INTX_FORMAT,
129 is_vtable_stub? "vtbl": "itbl", vtable_index, p2i(VtableStub::receiver_location()));
156 return s;
157 }
158
159
160 void VtableStubs::enter(bool is_vtable_stub, int vtable_index, VtableStub* s) {
161 MutexLocker ml(VtableStubs_lock);
162 assert(s->matches(is_vtable_stub, vtable_index), "bad vtable stub");
163 unsigned int h = VtableStubs::hash(is_vtable_stub, vtable_index);
164 // enter s at the beginning of the corresponding list
165 s->set_next(_table[h]);
166 _table[h] = s;
167 _number_of_vtable_stubs++;
168 }
169
170 VtableStub* VtableStubs::entry_point(address pc) {
171 MutexLocker ml(VtableStubs_lock);
172 VtableStub* stub = (VtableStub*)(pc - VtableStub::entry_offset());
173 uint hash = VtableStubs::hash(stub->is_vtable_stub(), stub->index());
174 VtableStub* s;
175 for (s = _table[hash]; s != NULL && s != stub; s = s->next()) {}
176 if (s == stub) {
177 return s;
178 }
179 return NULL;
180 }
181
182 bool VtableStubs::contains(address pc) {
183 // simple solution for now - we may want to use
184 // a faster way if this function is called often
185 return stub_containing(pc) != NULL;
186 }
187
188
189 VtableStub* VtableStubs::stub_containing(address pc) {
190 // Note: No locking needed since any change to the data structure
191 // happens with an atomic store into it (we don't care about
192 // consistency with the _number_of_vtable_stubs counter).
193 for (int i = 0; i < N; i++) {
194 for (VtableStub* s = _table[i]; s != NULL; s = s->next()) {
195 if (s->contains(pc)) return s;
196 }
197 }
198 return NULL;
199 }
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73 void* res = _chunk;
74 _chunk += real_size;
75 align_chunk();
76 return res;
77 }
78
79
80 void VtableStub::print_on(outputStream* st) const {
81 st->print("vtable stub (index = %d, receiver_location = " INTX_FORMAT ", code = [" INTPTR_FORMAT ", " INTPTR_FORMAT "[)",
82 index(), p2i(receiver_location()), p2i(code_begin()), p2i(code_end()));
83 }
84
85
86 // -----------------------------------------------------------------------------------------
87 // Implementation of VtableStubs
88 //
89 // For each hash value there's a linked list of vtable stubs (with that
90 // hash value). Each list is anchored in a little hash _table, indexed
91 // by that hash value.
92
93 static int const firstStub_size = 1024;
94
95 VtableStub* VtableStubs::_table[VtableStubs::N];
96 int VtableStubs::_number_of_vtable_stubs = 0;
97 int VtableStubs::_vtab_stub_size = 0;
98 int VtableStubs::_itab_stub_size = 0;
99
100
101 void VtableStubs::initialize() {
102 VtableStub::_receiver_location = SharedRuntime::name_for_receiver();
103 {
104 MutexLocker ml(VtableStubs_lock);
105 assert(_number_of_vtable_stubs == 0, "potential performance bug: VtableStubs initialized more than once");
106 assert(is_power_of_2(N), "N must be a power of 2");
107 for (int i = 0; i < N; i++) {
108 _table[i] = NULL;
109 }
110 }
111 }
112
113
114 int VtableStub::code_size_limit(bool is_vtable_stub) {
115 if (is_vtable_stub) {
116 return VtableStubs::_vtab_stub_size > 0 ? VtableStubs::_vtab_stub_size
117 : firstStub_size;
118 } else { // itable stub
119 return VtableStubs::_itab_stub_size > 0 ? VtableStubs::_itab_stub_size
120 : firstStub_size;
121 }
122 } // code_size_limit
123
124
125 void VtableStub::check_and_set_size_limit(bool is_vtable_stub,
126 int code_size,
127 int padding ) {
128 const char* name = is_vtable_stub ? "vtable" : "itable";
129
130 guarantee(code_size <= code_size_limit(is_vtable_stub),
131 "buffer overflow in %s stub, code_size is %d, limit is %d", name, code_size, code_size_limit(is_vtable_stub));
132
133 if (is_vtable_stub) {
134 if (log_is_enabled(Trace, vtablestubs)) {
135 if ( (VtableStubs::_vtab_stub_size > 0) && ((code_size + padding) > VtableStubs::_vtab_stub_size) ) {
136 log_trace(vtablestubs)("%s size estimate needed adjustment from %d to %d bytes",
137 name, VtableStubs::_vtab_stub_size, code_size + padding);
138 }
139 }
140 if ( (code_size + padding) > VtableStubs::_vtab_stub_size ) {
141 VtableStubs::_vtab_stub_size = code_size + padding;
142 }
143 } else { // itable stub
144 if (log_is_enabled(Trace, vtablestubs)) {
145 if ( (VtableStubs::_itab_stub_size > 0) && ((code_size + padding) > VtableStubs::_itab_stub_size) ) {
146 log_trace(vtablestubs)("%s size estimate needed adjustment from %d to %d bytes",
147 name, VtableStubs::_itab_stub_size, code_size + padding);
148 }
149 }
150 if ( (code_size + padding) > VtableStubs::_itab_stub_size ) {
151 VtableStubs::_itab_stub_size = code_size + padding;
152 }
153 }
154 return;
155 } // check_and_set_size_limit
156
157
158 void VtableStubs::bookkeeping(MacroAssembler* masm, outputStream* out, VtableStub* s,
159 address npe_addr, address ame_addr, bool is_vtable_stub,
160 int index, int slop_bytes, int slop32) {
161 const char* name = is_vtable_stub ? "vtable" : "itable";
162 const int stub_length = VtableStub::code_size_limit(is_vtable_stub);
163
164 if (log_is_enabled(Trace, vtablestubs)) {
165 log_trace(vtablestubs)("%s #%d at " PTR_FORMAT ": size: %d, estimate: %d, slop area: %d",
166 name, index, p2i(s->code_begin()),
167 (int)(masm->pc() - s->code_begin()),
168 stub_length,
169 (int)(s->code_end() - masm->pc()));
170 }
171 guarantee(masm->pc() <= s->code_end(), "%s #%d: overflowed buffer, estimated len: %d, actual len: %d, overrun: %d",
172 name, index, stub_length,
173 (int)(masm->pc() - s->code_begin()),
174 (int)(masm->pc() - s->code_end()));
175 assert((masm->pc() + slop32) <= s->code_end(), "%s #%d: spare space for 32-bit offset: required = %d, available = %d",
176 name, index, slop32,
177 (int)(s->code_end() - masm->pc()));
178
179 // After the first vtable/itable stub is generated, we have a much
180 // better estimate for the stub size. Remember/update this
181 // estimate after some sanity checks.
182 s->check_and_set_size_limit(is_vtable_stub, masm->offset(), slop_bytes);
183 s->set_exception_points(npe_addr, ame_addr);
184 }
185
186
187 address VtableStubs::find_stub(bool is_vtable_stub, int vtable_index) {
188 assert(vtable_index >= 0, "must be positive");
189
190 VtableStub* s = ShareVtableStubs ? lookup(is_vtable_stub, vtable_index) : NULL;
191 if (s == NULL) {
192 if (is_vtable_stub) {
193 s = create_vtable_stub(vtable_index);
194 } else {
195 s = create_itable_stub(vtable_index);
196 }
197
198 // Creation of vtable or itable can fail if there is not enough free space in the code cache.
199 if (s == NULL) {
200 return NULL;
201 }
202
203 enter(is_vtable_stub, vtable_index, s);
204 if (PrintAdapterHandlers) {
205 tty->print_cr("Decoding VtableStub %s[%d]@" INTX_FORMAT,
206 is_vtable_stub? "vtbl": "itbl", vtable_index, p2i(VtableStub::receiver_location()));
233 return s;
234 }
235
236
237 void VtableStubs::enter(bool is_vtable_stub, int vtable_index, VtableStub* s) {
238 MutexLocker ml(VtableStubs_lock);
239 assert(s->matches(is_vtable_stub, vtable_index), "bad vtable stub");
240 unsigned int h = VtableStubs::hash(is_vtable_stub, vtable_index);
241 // enter s at the beginning of the corresponding list
242 s->set_next(_table[h]);
243 _table[h] = s;
244 _number_of_vtable_stubs++;
245 }
246
247 VtableStub* VtableStubs::entry_point(address pc) {
248 MutexLocker ml(VtableStubs_lock);
249 VtableStub* stub = (VtableStub*)(pc - VtableStub::entry_offset());
250 uint hash = VtableStubs::hash(stub->is_vtable_stub(), stub->index());
251 VtableStub* s;
252 for (s = _table[hash]; s != NULL && s != stub; s = s->next()) {}
253 return (s == stub) ? s : NULL;
254 }
255
256 bool VtableStubs::contains(address pc) {
257 // simple solution for now - we may want to use
258 // a faster way if this function is called often
259 return stub_containing(pc) != NULL;
260 }
261
262
263 VtableStub* VtableStubs::stub_containing(address pc) {
264 // Note: No locking needed since any change to the data structure
265 // happens with an atomic store into it (we don't care about
266 // consistency with the _number_of_vtable_stubs counter).
267 for (int i = 0; i < N; i++) {
268 for (VtableStub* s = _table[i]; s != NULL; s = s->next()) {
269 if (s->contains(pc)) return s;
270 }
271 }
272 return NULL;
273 }
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