1 /* 2 * Copyright (c) 2003, 2016, 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 // 36 // Note that most applications load thousands of methods, so keeping the size of this 37 // structure small has a big impact on footprint. 38 39 // The actual bytecodes are inlined after the end of the ConstMethod struct. 40 // 41 // The line number table is compressed and inlined following the byte codes. It is 42 // found as the first byte following the byte codes. Note that accessing the line 43 // number and local variable tables is not performance critical at all. 44 // 45 // The checked exceptions table and the local variable table are inlined after the 46 // line number table, and indexed from the end of the method. We do not compress the 47 // checked exceptions table since the average length is less than 2, and it is used 48 // by reflection so access should be fast. We do not bother to compress the local 49 // variable table either since it is mostly absent. 50 // 51 // 52 // ConstMethod embedded field layout (after declared fields): 53 // [EMBEDDED byte codes] 54 // [EMBEDDED compressed linenumber table] 55 // (see class CompressedLineNumberReadStream) 56 // (note that length is unknown until decompressed) 57 // (access flags bit tells whether table is present) 58 // (indexed from start of ConstMethod) 59 // (elements not necessarily sorted!) 60 // [EMBEDDED localvariable table elements + length (length last)] 61 // (length is u2, elements are 6-tuples of u2) 62 // (see class LocalVariableTableElement) 63 // (access flags bit tells whether table is present) 64 // (indexed from end of ConstMethod*) 65 // [EMBEDDED exception table + length (length last)] 66 // (length is u2, elements are 4-tuples of u2) 67 // (see class ExceptionTableElement) 68 // (access flags bit tells whether table is present) 69 // (indexed from end of ConstMethod*) 70 // [EMBEDDED checked exceptions elements + length (length last)] 71 // (length is u2, elements are u2) 72 // (see class CheckedExceptionElement) 73 // (access flags bit tells whether table is present) 74 // (indexed from end of ConstMethod*) 75 // [EMBEDDED method parameters elements + length (length last)] 76 // (length is u2, elements are u2, u4 structures) 77 // (see class MethodParametersElement) 78 // (access flags bit tells whether table is present) 79 // (indexed from end of ConstMethod*) 80 // [EMBEDDED generic signature index (u2)] 81 // (indexed from end of constMethodOop) 82 // [EMBEDDED annotations arrays - method, parameter, type, default] 83 // pointer to Array<u1> if annotation is present 84 // 85 // IMPORTANT: If anything gets added here, there need to be changes to 86 // ensure that ServicabilityAgent doesn't get broken as a result! 87 88 89 // Utility class describing elements in checked exceptions table inlined in Method*. 90 class CheckedExceptionElement VALUE_OBJ_CLASS_SPEC { 91 public: 92 u2 class_cp_index; 93 }; 94 95 96 // Utility class describing elements in local variable table inlined in Method*. 97 class LocalVariableTableElement VALUE_OBJ_CLASS_SPEC { 98 public: 99 u2 start_bci; 100 u2 length; 101 u2 name_cp_index; 102 u2 descriptor_cp_index; 103 u2 signature_cp_index; 104 u2 slot; 105 }; 106 107 // Utility class describing elements in exception table 108 class ExceptionTableElement VALUE_OBJ_CLASS_SPEC { 109 public: 110 u2 start_pc; 111 u2 end_pc; 112 u2 handler_pc; 113 u2 catch_type_index; 114 }; 115 116 // Utility class describing elements in method parameters 117 class MethodParametersElement VALUE_OBJ_CLASS_SPEC { 118 public: 119 u2 name_cp_index; 120 u2 flags; 121 }; 122 123 class KlassSizeStats; 124 class AdapterHandlerEntry; 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 class ConstMethod : public MetaspaceObj { 171 friend class VMStructs; 172 friend class JVMCIVMStructs; 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 // Adapter blob (i2c/c2i) for this Method*. Set once when method is linked. 206 union { 207 AdapterHandlerEntry* _adapter; 208 AdapterHandlerEntry** _adapter_trampoline; 209 }; 210 211 int _constMethod_size; 212 u2 _flags; 213 214 // Size of Java bytecodes allocated immediately after Method*. 215 u2 _code_size; 216 u2 _name_index; // Method name (index in constant pool) 217 u2 _signature_index; // Method signature (index in constant pool) 218 u2 _method_idnum; // unique identification number for the method within the class 219 // initially corresponds to the index into the methods array. 220 // but this may change with redefinition 221 u2 _max_stack; // Maximum number of entries on the expression stack 222 u2 _max_locals; // Number of local variables used by this method 223 u2 _size_of_parameters; // size of the parameter block (receiver + arguments) in words 224 u2 _orig_method_idnum; // Original unique identification number for the method 225 226 // Constructor 227 ConstMethod(int byte_code_size, 228 InlineTableSizes* sizes, 229 MethodType is_overpass, 230 int size); 231 public: 232 233 static ConstMethod* allocate(ClassLoaderData* loader_data, 234 int byte_code_size, 235 InlineTableSizes* sizes, 236 MethodType mt, 237 TRAPS); 238 239 bool is_constMethod() const { return true; } 240 241 // Inlined tables 242 void set_inlined_tables_length(InlineTableSizes* sizes); 243 244 bool has_generic_signature() const 245 { return (_flags & _has_generic_signature) != 0; } 246 247 bool has_linenumber_table() const 248 { return (_flags & _has_linenumber_table) != 0; } 249 250 bool has_checked_exceptions() const 251 { return (_flags & _has_checked_exceptions) != 0; } 252 253 bool has_localvariable_table() const 254 { return (_flags & _has_localvariable_table) != 0; } 255 256 bool has_exception_handler() const 257 { return (_flags & _has_exception_table) != 0; } 258 259 bool has_method_parameters() const 260 { return (_flags & _has_method_parameters) != 0; } 261 262 MethodType method_type() const { 263 return ((_flags & _is_overpass) == 0) ? NORMAL : OVERPASS; 264 } 265 266 void set_method_type(MethodType mt) { 267 if (mt == NORMAL) { 268 _flags &= ~(_is_overpass); 269 } else { 270 _flags |= _is_overpass; 271 } 272 } 273 274 // constant pool 275 ConstantPool* constants() const { return _constants; } 276 void set_constants(ConstantPool* c) { _constants = c; } 277 278 Method* method() const; 279 280 // stackmap table data 281 Array<u1>* stackmap_data() const { return _stackmap_data; } 282 void set_stackmap_data(Array<u1>* sd) { _stackmap_data = sd; } 283 void copy_stackmap_data(ClassLoaderData* loader_data, u1* sd, int length, TRAPS); 284 bool has_stackmap_table() const { return _stackmap_data != NULL; } 285 286 // adapter 287 void set_adapter_entry(AdapterHandlerEntry* adapter) { 288 assert(!is_shared(), "shared methods have fixed adapter_trampoline"); 289 _adapter = adapter; 290 } 291 void set_adapter_trampoline(AdapterHandlerEntry** trampoline) { 292 assert(DumpSharedSpaces, "must be"); 293 assert(*trampoline == NULL, "must be NULL during dump time, to be initialized at run time"); 294 _adapter_trampoline = trampoline; 295 } 296 void update_adapter_trampoline(AdapterHandlerEntry* adapter) { 297 assert(is_shared(), "must be"); 298 *_adapter_trampoline = adapter; 299 assert(this->adapter() == adapter, "must be"); 300 } 301 AdapterHandlerEntry* adapter() { 302 if (is_shared()) { 303 return *_adapter_trampoline; 304 } else { 305 return _adapter; 306 } 307 } 308 309 void init_fingerprint() { 310 const uint64_t initval = UCONST64(0x8000000000000000); 311 _fingerprint = initval; 312 } 313 314 uint64_t fingerprint() const { 315 // Since reads aren't atomic for 64 bits, if any of the high or low order 316 // word is the initial value, return 0. See init_fingerprint for initval. 317 uint high_fp = (uint)(_fingerprint >> 32); 318 if ((int) _fingerprint == 0 || high_fp == 0x80000000) { 319 return 0L; 320 } else { 321 return _fingerprint; 322 } 323 } 324 325 uint64_t set_fingerprint(uint64_t new_fingerprint) { 326 #ifdef ASSERT 327 // Assert only valid if complete/valid 64 bit _fingerprint value is read. 328 uint64_t oldfp = fingerprint(); 329 #endif // ASSERT 330 _fingerprint = new_fingerprint; 331 assert(oldfp == 0L || new_fingerprint == oldfp, 332 "fingerprint cannot change"); 333 assert(((new_fingerprint >> 32) != 0x80000000) && (int)new_fingerprint !=0, 334 "fingerprint should call init to set initial value"); 335 return new_fingerprint; 336 } 337 338 // name 339 int name_index() const { return _name_index; } 340 void set_name_index(int index) { _name_index = index; } 341 342 // signature 343 int signature_index() const { return _signature_index; } 344 void set_signature_index(int index) { _signature_index = index; } 345 346 // generics support 347 int generic_signature_index() const { 348 if (has_generic_signature()) { 349 return *generic_signature_index_addr(); 350 } else { 351 return 0; 352 } 353 } 354 void set_generic_signature_index(u2 index) { 355 assert(has_generic_signature(), ""); 356 u2* addr = generic_signature_index_addr(); 357 *addr = index; 358 } 359 360 // Sizing 361 static int header_size() { return sizeof(ConstMethod)/wordSize; } 362 363 // Size needed 364 static int size(int code_size, InlineTableSizes* sizes); 365 366 int size() const { return _constMethod_size;} 367 void set_constMethod_size(int size) { _constMethod_size = size; } 368 #if INCLUDE_SERVICES 369 void collect_statistics(KlassSizeStats *sz) const; 370 #endif 371 372 // code size 373 int code_size() const { return _code_size; } 374 void set_code_size(int size) { 375 assert(max_method_code_size < (1 << 16), 376 "u2 is too small to hold method code size in general"); 377 assert(0 <= size && size <= max_method_code_size, "invalid code size"); 378 _code_size = size; 379 } 380 381 // linenumber table - note that length is unknown until decompression, 382 // see class CompressedLineNumberReadStream. 383 u_char* compressed_linenumber_table() const; // not preserved by gc 384 u2* generic_signature_index_addr() const; 385 u2* checked_exceptions_length_addr() const; 386 u2* localvariable_table_length_addr() const; 387 u2* exception_table_length_addr() const; 388 u2* method_parameters_length_addr() const; 389 390 // checked exceptions 391 int checked_exceptions_length() const; 392 CheckedExceptionElement* checked_exceptions_start() const; 393 394 // localvariable table 395 int localvariable_table_length() const; 396 LocalVariableTableElement* localvariable_table_start() const; 397 398 // exception table 399 int exception_table_length() const; 400 ExceptionTableElement* exception_table_start() const; 401 402 // method parameters table 403 404 // This returns -1 if no parameters are present, a non-negative 405 // value otherwise. Note: sometimes, there are 0-length parameters 406 // attributes that must be reported up to the reflection API all the 407 // same. 408 int method_parameters_length() const; 409 MethodParametersElement* method_parameters_start() const; 410 411 // method annotations 412 bool has_method_annotations() const 413 { return (_flags & _has_method_annotations) != 0; } 414 415 bool has_parameter_annotations() const 416 { return (_flags & _has_parameter_annotations) != 0; } 417 418 bool has_type_annotations() const 419 { return (_flags & _has_type_annotations) != 0; } 420 421 bool has_default_annotations() const 422 { return (_flags & _has_default_annotations) != 0; } 423 424 425 AnnotationArray** method_annotations_addr() const; 426 AnnotationArray* method_annotations() const { 427 return has_method_annotations() ? *(method_annotations_addr()) : NULL; 428 } 429 void set_method_annotations(AnnotationArray* anno) { 430 *(method_annotations_addr()) = anno; 431 } 432 433 AnnotationArray** parameter_annotations_addr() const; 434 AnnotationArray* parameter_annotations() const { 435 return has_parameter_annotations() ? *(parameter_annotations_addr()) : NULL; 436 } 437 void set_parameter_annotations(AnnotationArray* anno) { 438 *(parameter_annotations_addr()) = anno; 439 } 440 441 AnnotationArray** type_annotations_addr() const; 442 AnnotationArray* type_annotations() const { 443 return has_type_annotations() ? *(type_annotations_addr()) : NULL; 444 } 445 void set_type_annotations(AnnotationArray* anno) { 446 *(type_annotations_addr()) = anno; 447 } 448 449 AnnotationArray** default_annotations_addr() const; 450 AnnotationArray* default_annotations() const { 451 return has_default_annotations() ? *(default_annotations_addr()) : NULL; 452 } 453 void set_default_annotations(AnnotationArray* anno) { 454 *(default_annotations_addr()) = anno; 455 } 456 457 int method_annotations_length() const { 458 return has_method_annotations() ? method_annotations()->length() : 0; 459 } 460 int parameter_annotations_length() const { 461 return has_parameter_annotations() ? parameter_annotations()->length() : 0; 462 } 463 int type_annotations_length() const { 464 return has_type_annotations() ? type_annotations()->length() : 0; 465 } 466 int default_annotations_length() const { 467 return has_default_annotations() ? default_annotations()->length() : 0; 468 } 469 470 // Copy annotations from other ConstMethod 471 void copy_annotations_from(ConstMethod* cm); 472 473 // byte codes 474 void set_code(address code) { 475 if (code_size() > 0) { 476 memcpy(code_base(), code, code_size()); 477 } 478 } 479 address code_base() const { return (address) (this+1); } 480 address code_end() const { return code_base() + code_size(); } 481 bool contains(address bcp) const { return code_base() <= bcp 482 && bcp < code_end(); } 483 // Offset to bytecodes 484 static ByteSize codes_offset() 485 { return in_ByteSize(sizeof(ConstMethod)); } 486 487 static ByteSize constants_offset() 488 { return byte_offset_of(ConstMethod, _constants); } 489 490 static ByteSize max_stack_offset() 491 { return byte_offset_of(ConstMethod, _max_stack); } 492 static ByteSize size_of_locals_offset() 493 { return byte_offset_of(ConstMethod, _max_locals); } 494 static ByteSize size_of_parameters_offset() 495 { return byte_offset_of(ConstMethod, _size_of_parameters); } 496 497 498 // Unique id for the method 499 static const u2 MAX_IDNUM; 500 static const u2 UNSET_IDNUM; 501 u2 method_idnum() const { return _method_idnum; } 502 void set_method_idnum(u2 idnum) { _method_idnum = idnum; } 503 504 u2 orig_method_idnum() const { return _orig_method_idnum; } 505 void set_orig_method_idnum(u2 idnum) { _orig_method_idnum = idnum; } 506 507 // max stack 508 int max_stack() const { return _max_stack; } 509 void set_max_stack(int size) { _max_stack = size; } 510 511 // max locals 512 int max_locals() const { return _max_locals; } 513 void set_max_locals(int size) { _max_locals = size; } 514 515 // size of parameters 516 int size_of_parameters() const { return _size_of_parameters; } 517 void set_size_of_parameters(int size) { _size_of_parameters = size; } 518 519 // Deallocation for RedefineClasses 520 void deallocate_contents(ClassLoaderData* loader_data); 521 bool is_klass() const { return false; } 522 DEBUG_ONLY(bool on_stack() { return false; }) 523 524 private: 525 // Since the size of the compressed line number table is unknown, the 526 // offsets of the other variable sized sections are computed backwards 527 // from the end of the ConstMethod*. 528 529 // First byte after ConstMethod* 530 address constMethod_end() const 531 { return (address)((intptr_t*)this + _constMethod_size); } 532 533 // Last short in ConstMethod* 534 u2* last_u2_element() const; 535 536 public: 537 // Printing 538 void print_on (outputStream* st) const; 539 void print_value_on(outputStream* st) const; 540 541 const char* internal_name() const { return "{constMethod}"; } 542 543 // Verify 544 void verify_on(outputStream* st); 545 }; 546 547 #endif // SHARE_VM_OOPS_CONSTMETHODOOP_HPP