1 /* 2 * Copyright (c) 2003, 2014, 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 are not written to after 31 // the classfile is parsed(*see below). This part of the method can be shared across 32 // processes in a read-only section with Class Data Sharing (CDS). It's important 33 // that this class doesn't have virtual functions because the vptr cannot be shared 34 // with CDS. 35 // (*)RewriteByteCodes and RewriteFrequentPairs is an exception but turned off in CDS 36 // 37 // Note that most applications load thousands of methods, so keeping the size of this 38 // structure small has a big impact on footprint. 39 40 // The actual bytecodes are inlined after the end of the ConstMethod struct. 41 // 42 // The line number table is compressed and inlined following the byte codes. It is 43 // found as the first byte following the byte codes. Note that accessing the line 44 // number and local variable tables is not performance critical at all. 45 // 46 // The checked exceptions table and the local variable table are inlined after the 47 // line number table, and indexed from the end of the method. We do not compress the 48 // checked exceptions table since the average length is less than 2, and it is used 49 // by reflection so access should be fast. We do not bother to compress the local 50 // variable table either since it is mostly absent. 51 // 52 // 53 // ConstMethod embedded field layout (after declared fields): 54 // [EMBEDDED byte codes] 55 // [EMBEDDED 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 // [EMBEDDED localvariable table elements + length (length last)] 62 // (length is u2, elements are 6-tuples of u2) 63 // (see class LocalVariableTableElement) 64 // (access flags bit tells whether table is present) 65 // (indexed from end of ConstMethod*) 66 // [EMBEDDED exception table + length (length last)] 67 // (length is u2, elements are 4-tuples of u2) 68 // (see class ExceptionTableElement) 69 // (access flags bit tells whether table is present) 70 // (indexed from end of ConstMethod*) 71 // [EMBEDDED checked exceptions elements + length (length last)] 72 // (length is u2, elements are u2) 73 // (see class CheckedExceptionElement) 74 // (access flags bit tells whether table is present) 75 // (indexed from end of ConstMethod*) 76 // [EMBEDDED method parameters elements + length (length last)] 77 // (length is u2, elements are u2, u4 structures) 78 // (see class MethodParametersElement) 79 // (access flags bit tells whether table is present) 80 // (indexed from end of ConstMethod*) 81 // [EMBEDDED generic signature index (u2)] 82 // (indexed from end of constMethodOop) 83 // [EMBEDDED annotations arrays - method, parameter, type, default] 84 // pointer to Array<u1> if annotation is present 85 // 86 // IMPORTANT: If anything gets added here, there need to be changes to 87 // ensure that ServicabilityAgent doesn't get broken as a result! 88 89 90 // Utility class describing elements in checked exceptions table inlined in Method*. 91 class CheckedExceptionElement VALUE_OBJ_CLASS_SPEC { 92 public: 93 u2 class_cp_index; 94 }; 95 96 97 // Utility class describing elements in local variable table inlined in Method*. 98 class LocalVariableTableElement VALUE_OBJ_CLASS_SPEC { 99 public: 100 u2 start_bci; 101 u2 length; 102 u2 name_cp_index; 103 u2 descriptor_cp_index; 104 u2 signature_cp_index; 105 u2 slot; 106 }; 107 108 // Utility class describing elements in exception table 109 class ExceptionTableElement VALUE_OBJ_CLASS_SPEC { 110 public: 111 u2 start_pc; 112 u2 end_pc; 113 u2 handler_pc; 114 u2 catch_type_index; 115 }; 116 117 // Utility class describing elements in method parameters 118 class MethodParametersElement VALUE_OBJ_CLASS_SPEC { 119 public: 120 u2 name_cp_index; 121 u2 flags; 122 }; 123 124 class KlassSizeStats; 125 126 // Class to collect the sizes of ConstMethod inline tables 127 #define INLINE_TABLES_DO(do_element) \ 128 do_element(localvariable_table_length) \ 129 do_element(compressed_linenumber_size) \ 130 do_element(exception_table_length) \ 131 do_element(checked_exceptions_length) \ 132 do_element(method_parameters_length) \ 133 do_element(generic_signature_index) \ 134 do_element(method_annotations_length) \ 135 do_element(parameter_annotations_length) \ 136 do_element(type_annotations_length) \ 137 do_element(default_annotations_length) 138 139 #define INLINE_TABLE_DECLARE(sym) int _##sym; 140 #define INLINE_TABLE_PARAM(sym) int sym, 141 #define INLINE_TABLE_INIT(sym) _##sym(sym), 142 #define INLINE_TABLE_NULL(sym) _##sym(0), 143 #define INLINE_TABLE_ACCESSOR(sym) int sym() const { return _##sym; } 144 145 class InlineTableSizes : StackObj { 146 // declarations 147 INLINE_TABLES_DO(INLINE_TABLE_DECLARE) 148 int _end; 149 public: 150 InlineTableSizes( 151 INLINE_TABLES_DO(INLINE_TABLE_PARAM) 152 int end) : 153 INLINE_TABLES_DO(INLINE_TABLE_INIT) 154 _end(end) {} 155 156 // Default constructor for no inlined tables 157 InlineTableSizes() : 158 INLINE_TABLES_DO(INLINE_TABLE_NULL) 159 _end(0) {} 160 161 // Accessors 162 INLINE_TABLES_DO(INLINE_TABLE_ACCESSOR) 163 }; 164 #undef INLINE_TABLE_ACCESSOR 165 #undef INLINE_TABLE_NULL 166 #undef INLINE_TABLE_INIT 167 #undef INLINE_TABLE_PARAM 168 #undef INLINE_TABLE_DECLARE 169 170 171 class ConstMethod : public MetaspaceObj { 172 friend class VMStructs; 173 174 public: 175 typedef enum { NORMAL, OVERPASS } MethodType; 176 177 private: 178 enum { 179 _has_linenumber_table = 0x0001, 180 _has_checked_exceptions = 0x0002, 181 _has_localvariable_table = 0x0004, 182 _has_exception_table = 0x0008, 183 _has_generic_signature = 0x0010, 184 _has_method_parameters = 0x0020, 185 _is_overpass = 0x0040, 186 _has_method_annotations = 0x0080, 187 _has_parameter_annotations = 0x0100, 188 _has_type_annotations = 0x0200, 189 _has_default_annotations = 0x0400 190 }; 191 192 // Bit vector of signature 193 // Callers interpret 0=not initialized yet and 194 // -1=too many args to fix, must parse the slow way. 195 // The real initial value is special to account for nonatomicity of 64 bit 196 // loads and stores. This value may updated and read without a lock by 197 // multiple threads, so is volatile. 198 volatile uint64_t _fingerprint; 199 200 ConstantPool* _constants; // Constant pool 201 202 // Raw stackmap data for the method 203 Array<u1>* _stackmap_data; 204 205 int _constMethod_size; 206 u2 _flags; 207 208 // Size of Java bytecodes allocated immediately after Method*. 209 u2 _code_size; 210 u2 _name_index; // Method name (index in constant pool) 211 u2 _signature_index; // Method signature (index in constant pool) 212 u2 _method_idnum; // unique identification number for the method within the class 213 // initially corresponds to the index into the methods array. 214 // but this may change with redefinition 215 u2 _max_stack; // Maximum number of entries on the expression stack 216 u2 _max_locals; // Number of local variables used by this method 217 u2 _size_of_parameters; // size of the parameter block (receiver + arguments) in words 218 219 // Constructor 220 ConstMethod(int byte_code_size, 221 InlineTableSizes* sizes, 222 MethodType is_overpass, 223 int size); 224 public: 225 226 static ConstMethod* allocate(ClassLoaderData* loader_data, 227 int byte_code_size, 228 InlineTableSizes* sizes, 229 MethodType mt, 230 TRAPS); 231 232 bool is_constMethod() const { return true; } 233 234 // Inlined tables 235 void set_inlined_tables_length(InlineTableSizes* sizes); 236 237 bool has_generic_signature() const 238 { return (_flags & _has_generic_signature) != 0; } 239 240 bool has_linenumber_table() const 241 { return (_flags & _has_linenumber_table) != 0; } 242 243 bool has_checked_exceptions() const 244 { return (_flags & _has_checked_exceptions) != 0; } 245 246 bool has_localvariable_table() const 247 { return (_flags & _has_localvariable_table) != 0; } 248 249 bool has_exception_handler() const 250 { return (_flags & _has_exception_table) != 0; } 251 252 bool has_method_parameters() const 253 { return (_flags & _has_method_parameters) != 0; } 254 255 MethodType method_type() const { 256 return ((_flags & _is_overpass) == 0) ? NORMAL : OVERPASS; 257 } 258 259 void set_method_type(MethodType mt) { 260 if (mt == NORMAL) { 261 _flags &= ~(_is_overpass); 262 } else { 263 _flags |= _is_overpass; 264 } 265 } 266 267 // constant pool 268 ConstantPool* constants() const { return _constants; } 269 void set_constants(ConstantPool* c) { _constants = c; } 270 271 Method* method() const; 272 273 // stackmap table data 274 Array<u1>* stackmap_data() const { return _stackmap_data; } 275 void set_stackmap_data(Array<u1>* sd) { _stackmap_data = sd; } 276 void copy_stackmap_data(ClassLoaderData* loader_data, u1* sd, int length, TRAPS); 277 bool has_stackmap_table() const { return _stackmap_data != NULL; } 278 279 void init_fingerprint() { 280 const uint64_t initval = UCONST64(0x8000000000000000); 281 _fingerprint = initval; 282 } 283 284 uint64_t fingerprint() const { 285 // Since reads aren't atomic for 64 bits, if any of the high or low order 286 // word is the initial value, return 0. See init_fingerprint for initval. 287 uint high_fp = (uint)(_fingerprint >> 32); 288 if ((int) _fingerprint == 0 || high_fp == 0x80000000) { 289 return 0L; 290 } else { 291 return _fingerprint; 292 } 293 } 294 295 uint64_t set_fingerprint(uint64_t new_fingerprint) { 296 #ifdef ASSERT 297 // Assert only valid if complete/valid 64 bit _fingerprint value is read. 298 uint64_t oldfp = fingerprint(); 299 #endif // ASSERT 300 _fingerprint = new_fingerprint; 301 assert(oldfp == 0L || new_fingerprint == oldfp, 302 "fingerprint cannot change"); 303 assert(((new_fingerprint >> 32) != 0x80000000) && (int)new_fingerprint !=0, 304 "fingerprint should call init to set initial value"); 305 return new_fingerprint; 306 } 307 308 // name 309 int name_index() const { return _name_index; } 310 void set_name_index(int index) { _name_index = index; } 311 312 // signature 313 int signature_index() const { return _signature_index; } 314 void set_signature_index(int index) { _signature_index = index; } 315 316 // generics support 317 int generic_signature_index() const { 318 if (has_generic_signature()) { 319 return *generic_signature_index_addr(); 320 } else { 321 return 0; 322 } 323 } 324 void set_generic_signature_index(u2 index) { 325 assert(has_generic_signature(), ""); 326 u2* addr = generic_signature_index_addr(); 327 *addr = index; 328 } 329 330 // Sizing 331 static int header_size() { 332 return sizeof(ConstMethod)/HeapWordSize; 333 } 334 335 // Size needed 336 static int size(int code_size, InlineTableSizes* sizes); 337 338 int size() const { return _constMethod_size;} 339 void set_constMethod_size(int size) { _constMethod_size = size; } 340 #if INCLUDE_SERVICES 341 void collect_statistics(KlassSizeStats *sz) const; 342 #endif 343 344 // code size 345 int code_size() const { return _code_size; } 346 void set_code_size(int size) { 347 assert(max_method_code_size < (1 << 16), 348 "u2 is too small to hold method code size in general"); 349 assert(0 <= size && size <= max_method_code_size, "invalid code size"); 350 _code_size = size; 351 } 352 353 // linenumber table - note that length is unknown until decompression, 354 // see class CompressedLineNumberReadStream. 355 u_char* compressed_linenumber_table() const; // not preserved by gc 356 u2* generic_signature_index_addr() const; 357 u2* checked_exceptions_length_addr() const; 358 u2* localvariable_table_length_addr() const; 359 u2* exception_table_length_addr() const; 360 u2* method_parameters_length_addr() const; 361 362 // checked exceptions 363 int checked_exceptions_length() const; 364 CheckedExceptionElement* checked_exceptions_start() const; 365 366 // localvariable table 367 int localvariable_table_length() const; 368 LocalVariableTableElement* localvariable_table_start() const; 369 370 // exception table 371 int exception_table_length() const; 372 ExceptionTableElement* exception_table_start() const; 373 374 // method parameters table 375 376 // This returns -1 if no parameters are present, a non-negative 377 // value otherwise. Note: sometimes, there are 0-length parameters 378 // attributes that must be reported up to the reflection API all the 379 // same. 380 int method_parameters_length() const; 381 MethodParametersElement* method_parameters_start() const; 382 383 // method annotations 384 bool has_method_annotations() const 385 { return (_flags & _has_method_annotations) != 0; } 386 387 bool has_parameter_annotations() const 388 { return (_flags & _has_parameter_annotations) != 0; } 389 390 bool has_type_annotations() const 391 { return (_flags & _has_type_annotations) != 0; } 392 393 bool has_default_annotations() const 394 { return (_flags & _has_default_annotations) != 0; } 395 396 397 AnnotationArray** method_annotations_addr() const; 398 AnnotationArray* method_annotations() const { 399 return has_method_annotations() ? *(method_annotations_addr()) : NULL; 400 } 401 void set_method_annotations(AnnotationArray* anno) { 402 *(method_annotations_addr()) = anno; 403 } 404 405 AnnotationArray** parameter_annotations_addr() const; 406 AnnotationArray* parameter_annotations() const { 407 return has_parameter_annotations() ? *(parameter_annotations_addr()) : NULL; 408 } 409 void set_parameter_annotations(AnnotationArray* anno) { 410 *(parameter_annotations_addr()) = anno; 411 } 412 413 AnnotationArray** type_annotations_addr() const; 414 AnnotationArray* type_annotations() const { 415 return has_type_annotations() ? *(type_annotations_addr()) : NULL; 416 } 417 void set_type_annotations(AnnotationArray* anno) { 418 *(type_annotations_addr()) = anno; 419 } 420 421 AnnotationArray** default_annotations_addr() const; 422 AnnotationArray* default_annotations() const { 423 return has_default_annotations() ? *(default_annotations_addr()) : NULL; 424 } 425 void set_default_annotations(AnnotationArray* anno) { 426 *(default_annotations_addr()) = anno; 427 } 428 429 int method_annotations_length() const { 430 return has_method_annotations() ? method_annotations()->length() : 0; 431 } 432 int parameter_annotations_length() const { 433 return has_parameter_annotations() ? parameter_annotations()->length() : 0; 434 } 435 int type_annotations_length() const { 436 return has_type_annotations() ? type_annotations()->length() : 0; 437 } 438 int default_annotations_length() const { 439 return has_default_annotations() ? default_annotations()->length() : 0; 440 } 441 442 // Copy annotations from other ConstMethod 443 void copy_annotations_from(ConstMethod* cm); 444 445 // byte codes 446 void set_code(address code) { 447 if (code_size() > 0) { 448 memcpy(code_base(), code, code_size()); 449 } 450 } 451 address code_base() const { return (address) (this+1); } 452 address code_end() const { return code_base() + code_size(); } 453 bool contains(address bcp) const { return code_base() <= bcp 454 && bcp < code_end(); } 455 // Offset to bytecodes 456 static ByteSize codes_offset() 457 { return in_ByteSize(sizeof(ConstMethod)); } 458 459 static ByteSize constants_offset() 460 { return byte_offset_of(ConstMethod, _constants); } 461 462 static ByteSize max_stack_offset() 463 { return byte_offset_of(ConstMethod, _max_stack); } 464 static ByteSize size_of_locals_offset() 465 { return byte_offset_of(ConstMethod, _max_locals); } 466 static ByteSize size_of_parameters_offset() 467 { return byte_offset_of(ConstMethod, _size_of_parameters); } 468 469 470 // Unique id for the method 471 static const u2 MAX_IDNUM; 472 static const u2 UNSET_IDNUM; 473 u2 method_idnum() const { return _method_idnum; } 474 void set_method_idnum(u2 idnum) { _method_idnum = idnum; } 475 476 // max stack 477 int max_stack() const { return _max_stack; } 478 void set_max_stack(int size) { _max_stack = size; } 479 480 // max locals 481 int max_locals() const { return _max_locals; } 482 void set_max_locals(int size) { _max_locals = size; } 483 484 // size of parameters 485 int size_of_parameters() const { return _size_of_parameters; } 486 void set_size_of_parameters(int size) { _size_of_parameters = size; } 487 488 // Deallocation for RedefineClasses 489 void deallocate_contents(ClassLoaderData* loader_data); 490 bool is_klass() const { return false; } 491 DEBUG_ONLY(bool on_stack() { return false; }) 492 493 private: 494 // Since the size of the compressed line number table is unknown, the 495 // offsets of the other variable sized sections are computed backwards 496 // from the end of the ConstMethod*. 497 498 // First byte after ConstMethod* 499 address constMethod_end() const 500 { return (address)((intptr_t*)this + _constMethod_size); } 501 502 // Last short in ConstMethod* 503 u2* last_u2_element() const; 504 505 public: 506 // Printing 507 void print_on (outputStream* st) const; 508 void print_value_on(outputStream* st) const; 509 510 const char* internal_name() const { return "{constMethod}"; } 511 512 // Verify 513 void verify_on(outputStream* st); 514 }; 515 516 #endif // SHARE_VM_OOPS_CONSTMETHODOOP_HPP