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; // see comments around Method::link_method() 209 }; 210 211 int _constMethod_size; 212 u2 _flags; 213 u1 _result_type; // BasicType of result 214 215 // Size of Java bytecodes allocated immediately after Method*. 216 u2 _code_size; 217 u2 _name_index; // Method name (index in constant pool) 218 u2 _signature_index; // Method signature (index in constant pool) 219 u2 _method_idnum; // unique identification number for the method within the class 220 // initially corresponds to the index into the methods array. 221 // but this may change with redefinition 222 u2 _max_stack; // Maximum number of entries on the expression stack 223 u2 _max_locals; // Number of local variables used by this method 224 u2 _size_of_parameters; // size of the parameter block (receiver + arguments) in words 225 u2 _orig_method_idnum; // Original unique identification number for the method 226 227 // Constructor 228 ConstMethod(int byte_code_size, 229 InlineTableSizes* sizes, 230 MethodType is_overpass, 231 int size); 232 public: 233 234 static ConstMethod* allocate(ClassLoaderData* loader_data, 235 int byte_code_size, 236 InlineTableSizes* sizes, 237 MethodType mt, 238 TRAPS); 239 240 bool is_constMethod() const { return true; } 241 242 // Inlined tables 243 void set_inlined_tables_length(InlineTableSizes* sizes); 244 245 bool has_generic_signature() const 246 { return (_flags & _has_generic_signature) != 0; } 247 248 bool has_linenumber_table() const 249 { return (_flags & _has_linenumber_table) != 0; } 250 251 bool has_checked_exceptions() const 252 { return (_flags & _has_checked_exceptions) != 0; } 253 254 bool has_localvariable_table() const 255 { return (_flags & _has_localvariable_table) != 0; } 256 257 bool has_exception_handler() const 258 { return (_flags & _has_exception_table) != 0; } 259 260 bool has_method_parameters() const 261 { return (_flags & _has_method_parameters) != 0; } 262 263 MethodType method_type() const { 264 return ((_flags & _is_overpass) == 0) ? NORMAL : OVERPASS; 265 } 266 267 void set_method_type(MethodType mt) { 268 if (mt == NORMAL) { 269 _flags &= ~(_is_overpass); 270 } else { 271 _flags |= _is_overpass; 272 } 273 } 274 275 // constant pool 276 ConstantPool* constants() const { return _constants; } 277 void set_constants(ConstantPool* c) { _constants = c; } 278 279 Method* method() const; 280 281 // stackmap table data 282 Array<u1>* stackmap_data() const { return _stackmap_data; } 283 void set_stackmap_data(Array<u1>* sd) { _stackmap_data = sd; } 284 void copy_stackmap_data(ClassLoaderData* loader_data, u1* sd, int length, TRAPS); 285 bool has_stackmap_table() const { return _stackmap_data != NULL; } 286 287 // adapter 288 void set_adapter_entry(AdapterHandlerEntry* adapter) { 289 assert(!is_shared(), "shared methods have fixed adapter_trampoline"); 290 _adapter = adapter; 291 } 292 void set_adapter_trampoline(AdapterHandlerEntry** trampoline) { 293 assert(DumpSharedSpaces, "must be"); 294 assert(*trampoline == NULL, "must be NULL during dump time, to be initialized at run time"); 295 _adapter_trampoline = trampoline; 296 } 297 void update_adapter_trampoline(AdapterHandlerEntry* adapter) { 298 assert(is_shared(), "must be"); 299 *_adapter_trampoline = adapter; 300 assert(this->adapter() == adapter, "must be"); 301 } 302 AdapterHandlerEntry* adapter() { 303 if (is_shared()) { 304 return *_adapter_trampoline; 305 } else { 306 return _adapter; 307 } 308 } 309 310 void init_fingerprint() { 311 const uint64_t initval = UCONST64(0x8000000000000000); 312 _fingerprint = initval; 313 } 314 315 uint64_t fingerprint() const { 316 // Since reads aren't atomic for 64 bits, if any of the high or low order 317 // word is the initial value, return 0. See init_fingerprint for initval. 318 uint high_fp = (uint)(_fingerprint >> 32); 319 if ((int) _fingerprint == 0 || high_fp == 0x80000000) { 320 return 0L; 321 } else { 322 return _fingerprint; 323 } 324 } 325 326 uint64_t set_fingerprint(uint64_t new_fingerprint) { 327 #ifdef ASSERT 328 // Assert only valid if complete/valid 64 bit _fingerprint value is read. 329 uint64_t oldfp = fingerprint(); 330 #endif // ASSERT 331 _fingerprint = new_fingerprint; 332 assert(oldfp == 0L || new_fingerprint == oldfp, 333 "fingerprint cannot change"); 334 assert(((new_fingerprint >> 32) != 0x80000000) && (int)new_fingerprint !=0, 335 "fingerprint should call init to set initial value"); 336 return new_fingerprint; 337 } 338 339 // name 340 int name_index() const { return _name_index; } 341 void set_name_index(int index) { _name_index = index; } 342 343 // signature 344 int signature_index() const { return _signature_index; } 345 void set_signature_index(int index) { _signature_index = index; } 346 347 // generics support 348 int generic_signature_index() const { 349 if (has_generic_signature()) { 350 return *generic_signature_index_addr(); 351 } else { 352 return 0; 353 } 354 } 355 void set_generic_signature_index(u2 index) { 356 assert(has_generic_signature(), ""); 357 u2* addr = generic_signature_index_addr(); 358 *addr = index; 359 } 360 361 // Sizing 362 static int header_size() { return sizeof(ConstMethod)/wordSize; } 363 364 // Size needed 365 static int size(int code_size, InlineTableSizes* sizes); 366 367 int size() const { return _constMethod_size;} 368 void set_constMethod_size(int size) { _constMethod_size = size; } 369 #if INCLUDE_SERVICES 370 void collect_statistics(KlassSizeStats *sz) const; 371 #endif 372 373 // code size 374 int code_size() const { return _code_size; } 375 void set_code_size(int size) { 376 assert(max_method_code_size < (1 << 16), 377 "u2 is too small to hold method code size in general"); 378 assert(0 <= size && size <= max_method_code_size, "invalid code size"); 379 _code_size = size; 380 } 381 382 // linenumber table - note that length is unknown until decompression, 383 // see class CompressedLineNumberReadStream. 384 u_char* compressed_linenumber_table() const; // not preserved by gc 385 u2* generic_signature_index_addr() const; 386 u2* checked_exceptions_length_addr() const; 387 u2* localvariable_table_length_addr() const; 388 u2* exception_table_length_addr() const; 389 u2* method_parameters_length_addr() const; 390 391 // checked exceptions 392 int checked_exceptions_length() const; 393 CheckedExceptionElement* checked_exceptions_start() const; 394 395 // localvariable table 396 int localvariable_table_length() const; 397 LocalVariableTableElement* localvariable_table_start() const; 398 399 // exception table 400 int exception_table_length() const; 401 ExceptionTableElement* exception_table_start() const; 402 403 // method parameters table 404 405 // This returns -1 if no parameters are present, a non-negative 406 // value otherwise. Note: sometimes, there are 0-length parameters 407 // attributes that must be reported up to the reflection API all the 408 // same. 409 int method_parameters_length() const; 410 MethodParametersElement* method_parameters_start() const; 411 412 // method annotations 413 bool has_method_annotations() const 414 { return (_flags & _has_method_annotations) != 0; } 415 416 bool has_parameter_annotations() const 417 { return (_flags & _has_parameter_annotations) != 0; } 418 419 bool has_type_annotations() const 420 { return (_flags & _has_type_annotations) != 0; } 421 422 bool has_default_annotations() const 423 { return (_flags & _has_default_annotations) != 0; } 424 425 426 AnnotationArray** method_annotations_addr() const; 427 AnnotationArray* method_annotations() const { 428 return has_method_annotations() ? *(method_annotations_addr()) : NULL; 429 } 430 void set_method_annotations(AnnotationArray* anno) { 431 *(method_annotations_addr()) = anno; 432 } 433 434 AnnotationArray** parameter_annotations_addr() const; 435 AnnotationArray* parameter_annotations() const { 436 return has_parameter_annotations() ? *(parameter_annotations_addr()) : NULL; 437 } 438 void set_parameter_annotations(AnnotationArray* anno) { 439 *(parameter_annotations_addr()) = anno; 440 } 441 442 AnnotationArray** type_annotations_addr() const; 443 AnnotationArray* type_annotations() const { 444 return has_type_annotations() ? *(type_annotations_addr()) : NULL; 445 } 446 void set_type_annotations(AnnotationArray* anno) { 447 *(type_annotations_addr()) = anno; 448 } 449 450 AnnotationArray** default_annotations_addr() const; 451 AnnotationArray* default_annotations() const { 452 return has_default_annotations() ? *(default_annotations_addr()) : NULL; 453 } 454 void set_default_annotations(AnnotationArray* anno) { 455 *(default_annotations_addr()) = anno; 456 } 457 458 int method_annotations_length() const { 459 return has_method_annotations() ? method_annotations()->length() : 0; 460 } 461 int parameter_annotations_length() const { 462 return has_parameter_annotations() ? parameter_annotations()->length() : 0; 463 } 464 int type_annotations_length() const { 465 return has_type_annotations() ? type_annotations()->length() : 0; 466 } 467 int default_annotations_length() const { 468 return has_default_annotations() ? default_annotations()->length() : 0; 469 } 470 471 // Copy annotations from other ConstMethod 472 void copy_annotations_from(ClassLoaderData* loader_data, ConstMethod* cm, TRAPS); 473 474 // byte codes 475 void set_code(address code) { 476 if (code_size() > 0) { 477 memcpy(code_base(), code, code_size()); 478 } 479 } 480 address code_base() const { return (address) (this+1); } 481 address code_end() const { return code_base() + code_size(); } 482 bool contains(address bcp) const { return code_base() <= bcp 483 && bcp < code_end(); } 484 // Offset to bytecodes 485 static ByteSize codes_offset() 486 { return in_ByteSize(sizeof(ConstMethod)); } 487 488 static ByteSize constants_offset() 489 { return byte_offset_of(ConstMethod, _constants); } 490 491 static ByteSize max_stack_offset() 492 { return byte_offset_of(ConstMethod, _max_stack); } 493 static ByteSize size_of_locals_offset() 494 { return byte_offset_of(ConstMethod, _max_locals); } 495 static ByteSize size_of_parameters_offset() 496 { return byte_offset_of(ConstMethod, _size_of_parameters); } 497 498 static ByteSize result_type_offset() 499 { return byte_offset_of(ConstMethod, _result_type); } 500 501 // Unique id for the method 502 static const u2 MAX_IDNUM; 503 static const u2 UNSET_IDNUM; 504 u2 method_idnum() const { return _method_idnum; } 505 void set_method_idnum(u2 idnum) { _method_idnum = idnum; } 506 507 u2 orig_method_idnum() const { return _orig_method_idnum; } 508 void set_orig_method_idnum(u2 idnum) { _orig_method_idnum = idnum; } 509 510 // max stack 511 int max_stack() const { return _max_stack; } 512 void set_max_stack(int size) { _max_stack = size; } 513 514 // max locals 515 int max_locals() const { return _max_locals; } 516 void set_max_locals(int size) { _max_locals = size; } 517 518 // size of parameters 519 int size_of_parameters() const { return _size_of_parameters; } 520 void set_size_of_parameters(int size) { _size_of_parameters = size; } 521 522 void set_result_type(BasicType rt) { assert(rt < 16, "result type too large"); 523 _result_type = (u1)rt; } 524 // Deallocation for RedefineClasses 525 void deallocate_contents(ClassLoaderData* loader_data); 526 bool is_klass() const { return false; } 527 DEBUG_ONLY(bool on_stack() { return false; }) 528 529 private: 530 // Since the size of the compressed line number table is unknown, the 531 // offsets of the other variable sized sections are computed backwards 532 // from the end of the ConstMethod*. 533 534 // First byte after ConstMethod* 535 address constMethod_end() const 536 { return (address)((intptr_t*)this + _constMethod_size); } 537 538 // Last short in ConstMethod* 539 u2* last_u2_element() const; 540 541 public: 542 // Printing 543 void print_on (outputStream* st) const; 544 void print_value_on(outputStream* st) const; 545 546 const char* internal_name() const { return "{constMethod}"; } 547 548 // Verify 549 void verify_on(outputStream* st); 550 }; 551 552 #endif // SHARE_VM_OOPS_CONSTMETHODOOP_HPP