1 /* 2 * Copyright (c) 2003, 2012, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_VM_OOPS_CONSTMETHODOOP_HPP 26 #define SHARE_VM_OOPS_CONSTMETHODOOP_HPP 27 28 #include "oops/oop.hpp" 29 30 // An ConstMethod* represents portions of a Java method which 31 // do not vary. 32 // 33 // Memory layout (each line represents a word). Note that most 34 // applications load thousands of methods, so keeping the size of this 35 // structure small has a big impact on footprint. 36 // 37 // |------------------------------------------------------| 38 // | header | 39 // | klass | 40 // |------------------------------------------------------| 41 // | fingerprint 1 | 42 // | fingerprint 2 | 43 // | constants (oop) | 44 // | stackmap_data (oop) | 45 // | constMethod_size | 46 // | interp_kind | flags | code_size | 47 // | name index | signature index | 48 // | method_idnum | max_stack | 49 // | max_locals | size_of_parameters | 50 // |------------------------------------------------------| 51 // | | 52 // | byte codes | 53 // | | 54 // |------------------------------------------------------| 55 // | compressed linenumber table | 56 // | (see class CompressedLineNumberReadStream) | 57 // | (note that length is unknown until decompressed) | 58 // | (access flags bit tells whether table is present) | 59 // | (indexed from start of ConstMethod*) | 60 // | (elements not necessarily sorted!) | 61 // |------------------------------------------------------| 62 // | localvariable table elements + length (length last) | 63 // | (length is u2, elements are 6-tuples of u2) | 64 // | (see class LocalVariableTableElement) | 65 // | (access flags bit tells whether table is present) | 66 // | (indexed from end of ConstMethod*) | 67 // |------------------------------------------------------| 68 // | exception table + length (length last) | 69 // | (length is u2, elements are 4-tuples of u2) | 70 // | (see class ExceptionTableElement) | 71 // | (access flags bit tells whether table is present) | 72 // | (indexed from end of ConstMethod*) | 73 // |------------------------------------------------------| 74 // | checked exceptions elements + length (length last) | 75 // | (length is u2, elements are u2) | 76 // | (see class CheckedExceptionElement) | 77 // | (access flags bit tells whether table is present) | 78 // | (indexed from end of ConstMethod*) | 79 // |------------------------------------------------------| 80 // | generic signature index (u2) | 81 // | (indexed from start of constMethodOop) | 82 // |------------------------------------------------------| 83 84 85 // Utitily class decribing elements in checked exceptions table inlined in Method*. 86 class CheckedExceptionElement VALUE_OBJ_CLASS_SPEC { 87 public: 88 u2 class_cp_index; 89 }; 90 91 92 // Utitily class decribing elements in local variable table inlined in Method*. 93 class LocalVariableTableElement VALUE_OBJ_CLASS_SPEC { 94 public: 95 u2 start_bci; 96 u2 length; 97 u2 name_cp_index; 98 u2 descriptor_cp_index; 99 u2 signature_cp_index; 100 u2 slot; 101 }; 102 103 // Utitily class describing elements in exception table 104 class ExceptionTableElement VALUE_OBJ_CLASS_SPEC { 105 public: 106 u2 start_pc; 107 u2 end_pc; 108 u2 handler_pc; 109 u2 catch_type_index; 110 }; 111 112 113 class ConstMethod : public MetaspaceObj { 114 friend class VMStructs; 115 116 public: 117 typedef enum { NORMAL, OVERPASS } MethodType; 118 119 private: 120 enum { 121 _has_linenumber_table = 1, 122 _has_checked_exceptions = 2, 123 _has_localvariable_table = 4, 124 _has_exception_table = 8, 125 _has_generic_signature = 16, 126 _is_overpass = 32 127 }; 128 129 // Bit vector of signature 130 // Callers interpret 0=not initialized yet and 131 // -1=too many args to fix, must parse the slow way. 132 // The real initial value is special to account for nonatomicity of 64 bit 133 // loads and stores. This value may updated and read without a lock by 134 // multiple threads, so is volatile. 135 volatile uint64_t _fingerprint; 136 137 ConstantPool* _constants; // Constant pool 138 139 // Raw stackmap data for the method 140 Array<u1>* _stackmap_data; 141 142 int _constMethod_size; 143 jbyte _interpreter_kind; 144 jbyte _flags; 145 146 // Size of Java bytecodes allocated immediately after Method*. 147 u2 _code_size; 148 u2 _name_index; // Method name (index in constant pool) 149 u2 _signature_index; // Method signature (index in constant pool) 150 u2 _method_idnum; // unique identification number for the method within the class 151 // initially corresponds to the index into the methods array. 152 // but this may change with redefinition 153 u2 _max_stack; // Maximum number of entries on the expression stack 154 u2 _max_locals; // Number of local variables used by this method 155 u2 _size_of_parameters; // size of the parameter block (receiver + arguments) in words 156 157 // Constructor 158 ConstMethod(int byte_code_size, 159 int compressed_line_number_size, 160 int localvariable_table_length, 161 int exception_table_length, 162 int checked_exceptions_length, 163 u2 generic_signature_index, 164 MethodType is_overpass, 165 int size); 166 public: 167 168 static ConstMethod* allocate(ClassLoaderData* loader_data, 169 int byte_code_size, 170 int compressed_line_number_size, 171 int localvariable_table_length, 172 int exception_table_length, 173 int checked_exceptions_length, 174 u2 generic_signature_index, 175 MethodType mt, 176 TRAPS); 177 178 bool is_constMethod() const { return true; } 179 180 // Inlined tables 181 void set_inlined_tables_length(u2 generic_signature_index, 182 int checked_exceptions_len, 183 int compressed_line_number_size, 184 int localvariable_table_len, 185 int exception_table_len); 186 187 bool has_generic_signature() const 188 { return (_flags & _has_generic_signature) != 0; } 189 190 bool has_linenumber_table() const 191 { return (_flags & _has_linenumber_table) != 0; } 192 193 bool has_checked_exceptions() const 194 { return (_flags & _has_checked_exceptions) != 0; } 195 196 bool has_localvariable_table() const 197 { return (_flags & _has_localvariable_table) != 0; } 198 199 bool has_exception_handler() const 200 { return (_flags & _has_exception_table) != 0; } 201 202 MethodType method_type() const { 203 return ((_flags & _is_overpass) == 0) ? NORMAL : OVERPASS; 204 } 205 206 void set_method_type(MethodType mt) { 207 if (mt == NORMAL) { 208 _flags &= ~(_is_overpass); 209 } else { 210 _flags |= _is_overpass; 211 } 212 } 213 214 215 void set_interpreter_kind(int kind) { _interpreter_kind = kind; } 216 int interpreter_kind(void) const { return _interpreter_kind; } 217 218 // constant pool 219 ConstantPool* constants() const { return _constants; } 220 void set_constants(ConstantPool* c) { _constants = c; } 221 222 Method* method() const; 223 224 // stackmap table data 225 Array<u1>* stackmap_data() const { return _stackmap_data; } 226 void set_stackmap_data(Array<u1>* sd) { _stackmap_data = sd; } 227 bool has_stackmap_table() const { return _stackmap_data != NULL; } 228 229 void init_fingerprint() { 230 const uint64_t initval = CONST64(0x8000000000000000); 231 _fingerprint = initval; 232 } 233 234 uint64_t fingerprint() const { 235 // Since reads aren't atomic for 64 bits, if any of the high or low order 236 // word is the initial value, return 0. See init_fingerprint for initval. 237 uint high_fp = (uint)(_fingerprint >> 32); 238 if ((int) _fingerprint == 0 || high_fp == 0x80000000) { 239 return 0L; 240 } else { 241 return _fingerprint; 242 } 243 } 244 245 uint64_t set_fingerprint(uint64_t new_fingerprint) { 246 #ifdef ASSERT 247 // Assert only valid if complete/valid 64 bit _fingerprint value is read. 248 uint64_t oldfp = fingerprint(); 249 #endif // ASSERT 250 _fingerprint = new_fingerprint; 251 assert(oldfp == 0L || new_fingerprint == oldfp, 252 "fingerprint cannot change"); 253 assert(((new_fingerprint >> 32) != 0x80000000) && (int)new_fingerprint !=0, 254 "fingerprint should call init to set initial value"); 255 return new_fingerprint; 256 } 257 258 // name 259 int name_index() const { return _name_index; } 260 void set_name_index(int index) { _name_index = index; } 261 262 // signature 263 int signature_index() const { return _signature_index; } 264 void set_signature_index(int index) { _signature_index = index; } 265 266 // generics support 267 int generic_signature_index() const { 268 if (has_generic_signature()) { 269 return *generic_signature_index_addr(); 270 } else { 271 return 0; 272 } 273 } 274 void set_generic_signature_index(u2 index) { 275 assert(has_generic_signature(), ""); 276 u2* addr = generic_signature_index_addr(); 277 *addr = index; 278 } 279 280 // Sizing 281 static int header_size() { 282 return sizeof(ConstMethod)/HeapWordSize; 283 } 284 285 // Size needed 286 static int size(int code_size, int compressed_line_number_size, 287 int local_variable_table_length, 288 int exception_table_length, 289 int checked_exceptions_length, 290 u2 generic_signature_index); 291 292 int size() const { return _constMethod_size;} 293 void set_constMethod_size(int size) { _constMethod_size = size; } 294 295 // code size 296 int code_size() const { return _code_size; } 297 void set_code_size(int size) { 298 assert(max_method_code_size < (1 << 16), 299 "u2 is too small to hold method code size in general"); 300 assert(0 <= size && size <= max_method_code_size, "invalid code size"); 301 _code_size = size; 302 } 303 304 // linenumber table - note that length is unknown until decompression, 305 // see class CompressedLineNumberReadStream. 306 u_char* compressed_linenumber_table() const; // not preserved by gc 307 u2* generic_signature_index_addr() const; 308 u2* checked_exceptions_length_addr() const; 309 u2* localvariable_table_length_addr() const; 310 u2* exception_table_length_addr() const; 311 312 // checked exceptions 313 int checked_exceptions_length() const; 314 CheckedExceptionElement* checked_exceptions_start() const; 315 316 // localvariable table 317 int localvariable_table_length() const; 318 LocalVariableTableElement* localvariable_table_start() const; 319 320 // exception table 321 int exception_table_length() const; 322 ExceptionTableElement* exception_table_start() const; 323 324 // byte codes 325 void set_code(address code) { 326 if (code_size() > 0) { 327 memcpy(code_base(), code, code_size()); 328 } 329 } 330 address code_base() const { return (address) (this+1); } 331 address code_end() const { return code_base() + code_size(); } 332 bool contains(address bcp) const { return code_base() <= bcp 333 && bcp < code_end(); } 334 // Offset to bytecodes 335 static ByteSize codes_offset() 336 { return in_ByteSize(sizeof(ConstMethod)); } 337 338 static ByteSize constants_offset() 339 { return byte_offset_of(ConstMethod, _constants); } 340 341 static ByteSize max_stack_offset() 342 { return byte_offset_of(ConstMethod, _max_stack); } 343 static ByteSize size_of_locals_offset() 344 { return byte_offset_of(ConstMethod, _max_locals); } 345 static ByteSize size_of_parameters_offset() 346 { return byte_offset_of(ConstMethod, _size_of_parameters); } 347 348 349 // Unique id for the method 350 static const u2 MAX_IDNUM; 351 static const u2 UNSET_IDNUM; 352 u2 method_idnum() const { return _method_idnum; } 353 void set_method_idnum(u2 idnum) { _method_idnum = idnum; } 354 355 // max stack 356 int max_stack() const { return _max_stack; } 357 void set_max_stack(int size) { _max_stack = size; } 358 359 // max locals 360 int max_locals() const { return _max_locals; } 361 void set_max_locals(int size) { _max_locals = size; } 362 363 // size of parameters 364 int size_of_parameters() const { return _size_of_parameters; } 365 void set_size_of_parameters(int size) { _size_of_parameters = size; } 366 367 // Deallocation for RedefineClasses 368 void deallocate_contents(ClassLoaderData* loader_data); 369 bool is_klass() const { return false; } 370 DEBUG_ONLY(bool on_stack() { return false; }) 371 372 private: 373 // Since the size of the compressed line number table is unknown, the 374 // offsets of the other variable sized sections are computed backwards 375 // from the end of the ConstMethod*. 376 377 // First byte after ConstMethod* 378 address constMethod_end() const 379 { return (address)((oop*)this + _constMethod_size); } 380 381 // Last short in ConstMethod* 382 u2* last_u2_element() const 383 { return (u2*)constMethod_end() - 1; } 384 385 public: 386 // Printing 387 void print_on (outputStream* st) const; 388 void print_value_on(outputStream* st) const; 389 390 const char* internal_name() const { return "{constMethod}"; } 391 392 // Verify 393 void verify_on(outputStream* st); 394 }; 395 396 #endif // SHARE_VM_OOPS_CONSTMETHODOOP_HPP