1/* 2 * Copyright (c) 2003, 2017, 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#include "utilities/align.hpp" 30 31// An ConstMethod represents portions of a Java method which are not written to after 32// the classfile is parsed(*see below). This part of the method can be shared across 33// processes in a read-only section with Class Data Sharing (CDS). It's important 34// that this class doesn't have virtual functions because the vptr cannot be shared 35// with 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*. 91class 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*. 98class 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 109class 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 118class MethodParametersElement VALUE_OBJ_CLASS_SPEC { 119 public: 120 u2 name_cp_index; 121 u2 flags; 122}; 123 124class KlassSizeStats; 125class AdapterHandlerEntry; 126 127// Class to collect the sizes of ConstMethod inline tables 128#define INLINE_TABLES_DO(do_element) \ 129 do_element(localvariable_table_length) \ 130 do_element(compressed_linenumber_size) \ 131 do_element(exception_table_length) \ 132 do_element(checked_exceptions_length) \ 133 do_element(method_parameters_length) \ 134 do_element(generic_signature_index) \ 135 do_element(method_annotations_length) \ 136 do_element(parameter_annotations_length) \ 137 do_element(type_annotations_length) \ 138 do_element(default_annotations_length) 139 140#define INLINE_TABLE_DECLARE(sym) int _##sym; 141#define INLINE_TABLE_PARAM(sym) int sym, 142#define INLINE_TABLE_INIT(sym) _##sym(sym), 143#define INLINE_TABLE_NULL(sym) _##sym(0), 144#define INLINE_TABLE_ACCESSOR(sym) int sym() const { return _##sym; } 145 146class InlineTableSizes : StackObj { 147 // declarations 148 INLINE_TABLES_DO(INLINE_TABLE_DECLARE) 149 int _end; 150 public: 151 InlineTableSizes( 152 INLINE_TABLES_DO(INLINE_TABLE_PARAM) 153 int end) : 154 INLINE_TABLES_DO(INLINE_TABLE_INIT) 155 _end(end) {} 156 157 // Default constructor for no inlined tables 158 InlineTableSizes() : 159 INLINE_TABLES_DO(INLINE_TABLE_NULL) 160 _end(0) {} 161 162 // Accessors 163 INLINE_TABLES_DO(INLINE_TABLE_ACCESSOR) 164}; 165#undef INLINE_TABLE_ACCESSOR 166#undef INLINE_TABLE_NULL 167#undef INLINE_TABLE_INIT 168#undef INLINE_TABLE_PARAM 169#undef INLINE_TABLE_DECLARE 170 171class ConstMethod : public MetaspaceObj { 172 friend class VMStructs; 173 friend class JVMCIVMStructs; 174 175public: 176 typedef enum { NORMAL, OVERPASS } MethodType; 177 178private: 179 enum { 180 _has_linenumber_table = 0x0001, 181 _has_checked_exceptions = 0x0002, 182 _has_localvariable_table = 0x0004, 183 _has_exception_table = 0x0008, 184 _has_generic_signature = 0x0010, 185 _has_method_parameters = 0x0020, 186 _is_overpass = 0x0040, 187 _has_method_annotations = 0x0080, 188 _has_parameter_annotations = 0x0100, 189 _has_type_annotations = 0x0200, 190 _has_default_annotations = 0x0400 191 }; 192 193 // Bit vector of signature 194 // Callers interpret 0=not initialized yet and 195 // -1=too many args to fix, must parse the slow way. 196 // The real initial value is special to account for nonatomicity of 64 bit 197 // loads and stores. This value may updated and read without a lock by 198 // multiple threads, so is volatile. 199 volatile uint64_t _fingerprint; 200 201 // If you add a new field that points to any metaspace object, you 202 // must add this field to ConstMethod::metaspace_pointers_do(). 203 204 ConstantPool* _constants; // Constant pool 205 206 // Raw stackmap data for the method 207 Array<u1>* _stackmap_data; 208 209 // Adapter blob (i2c/c2i) for this Method*. Set once when method is linked. 210 union { 211 AdapterHandlerEntry* _adapter; 212 AdapterHandlerEntry** _adapter_trampoline; // see comments around Method::link_method() 213 }; 214 215 int _constMethod_size; 216 u2 _flags; 217 u1 _result_type; // BasicType of result 218 219 // Size of Java bytecodes allocated immediately after Method*. 220 u2 _code_size; 221 u2 _name_index; // Method name (index in constant pool) 222 u2 _signature_index; // Method signature (index in constant pool) 223 u2 _method_idnum; // unique identification number for the method within the class 224 // initially corresponds to the index into the methods array. 225 // but this may change with redefinition 226 u2 _max_stack; // Maximum number of entries on the expression stack 227 u2 _max_locals; // Number of local variables used by this method 228 u2 _size_of_parameters; // size of the parameter block (receiver + arguments) in words 229 u2 _orig_method_idnum; // Original unique identification number for the method 230 231 // Constructor 232 ConstMethod(int byte_code_size, 233 InlineTableSizes* sizes, 234 MethodType is_overpass, 235 int size); 236public: 237 238 static ConstMethod* allocate(ClassLoaderData* loader_data, 239 int byte_code_size, 240 InlineTableSizes* sizes, 241 MethodType mt, 242 TRAPS); 243 244 bool is_constMethod() const { return true; } 245 246 // Inlined tables 247 void set_inlined_tables_length(InlineTableSizes* sizes); 248 249 bool has_generic_signature() const 250 { return (_flags & _has_generic_signature) != 0; } 251 252 bool has_linenumber_table() const 253 { return (_flags & _has_linenumber_table) != 0; } 254 255 bool has_checked_exceptions() const 256 { return (_flags & _has_checked_exceptions) != 0; } 257 258 bool has_localvariable_table() const 259 { return (_flags & _has_localvariable_table) != 0; } 260 261 bool has_exception_handler() const 262 { return (_flags & _has_exception_table) != 0; } 263 264 bool has_method_parameters() const 265 { return (_flags & _has_method_parameters) != 0; } 266 267 MethodType method_type() const { 268 return ((_flags & _is_overpass) == 0) ? NORMAL : OVERPASS; 269 } 270 271 void set_method_type(MethodType mt) { 272 if (mt == NORMAL) { 273 _flags &= ~(_is_overpass); 274 } else { 275 _flags |= _is_overpass; 276 } 277 } 278 279 // constant pool 280 ConstantPool* constants() const { return _constants; } 281 void set_constants(ConstantPool* c) { _constants = c; } 282 283 Method* method() const; 284 285 // stackmap table data 286 Array<u1>* stackmap_data() const { return _stackmap_data; } 287 void set_stackmap_data(Array<u1>* sd) { _stackmap_data = sd; } 288 void copy_stackmap_data(ClassLoaderData* loader_data, u1* sd, int length, TRAPS); 289 bool has_stackmap_table() const { return _stackmap_data != NULL; } 290 291 // adapter 292 void set_adapter_entry(AdapterHandlerEntry* adapter) { 293 assert(!is_shared(), "shared methods have fixed adapter_trampoline"); 294 _adapter = adapter; 295 } 296 void set_adapter_trampoline(AdapterHandlerEntry** trampoline) { 297 assert(DumpSharedSpaces, "must be"); 298 assert(*trampoline == NULL, "must be NULL during dump time, to be initialized at run time"); 299 _adapter_trampoline = trampoline; 300 } 301 void update_adapter_trampoline(AdapterHandlerEntry* adapter) { 302 assert(is_shared(), "must be"); 303 *_adapter_trampoline = adapter; 304 assert(this->adapter() == adapter, "must be"); 305 } 306 AdapterHandlerEntry* adapter() { 307 if (is_shared()) { 308 return *_adapter_trampoline; 309 } else { 310 return _adapter; 311 } 312 } 313 314 void init_fingerprint() { 315 const uint64_t initval = UCONST64(0x8000000000000000); 316 _fingerprint = initval; 317 } 318 319 uint64_t fingerprint() const { 320 // Since reads aren't atomic for 64 bits, if any of the high or low order 321 // word is the initial value, return 0. See init_fingerprint for initval. 322 uint high_fp = (uint)(_fingerprint >> 32); 323 if ((int) _fingerprint == 0 || high_fp == 0x80000000) { 324 return 0L; 325 } else { 326 return _fingerprint; 327 } 328 } 329 330 uint64_t set_fingerprint(uint64_t new_fingerprint) { 331#ifdef ASSERT 332 // Assert only valid if complete/valid 64 bit _fingerprint value is read. 333 uint64_t oldfp = fingerprint(); 334#endif // ASSERT 335 _fingerprint = new_fingerprint; 336 assert(oldfp == 0L || new_fingerprint == oldfp, 337 "fingerprint cannot change"); 338 assert(((new_fingerprint >> 32) != 0x80000000) && (int)new_fingerprint !=0, 339 "fingerprint should call init to set initial value"); 340 return new_fingerprint; 341 } 342 343 // name 344 int name_index() const { return _name_index; } 345 void set_name_index(int index) { _name_index = index; } 346 347 // signature 348 int signature_index() const { return _signature_index; } 349 void set_signature_index(int index) { _signature_index = index; } 350 351 // generics support 352 int generic_signature_index() const { 353 if (has_generic_signature()) { 354 return *generic_signature_index_addr(); 355 } else { 356 return 0; 357 } 358 } 359 void set_generic_signature_index(u2 index) { 360 assert(has_generic_signature(), ""); 361 u2* addr = generic_signature_index_addr(); 362 *addr = index; 363 } 364 365 // Sizing 366 static int header_size() { 367 return align_up((int)sizeof(ConstMethod), wordSize) / wordSize; 368 } 369 370 // Size needed 371 static int size(int code_size, InlineTableSizes* sizes); 372 373 int size() const { return _constMethod_size;} 374 void set_constMethod_size(int size) { _constMethod_size = size; } 375 376 // ConstMethods should be stored in the read-only region of CDS archive. 377 static bool is_read_only_by_default() { return true; } 378 379#if INCLUDE_SERVICES 380 void collect_statistics(KlassSizeStats *sz) const; 381#endif 382 383 // code size 384 int code_size() const { return _code_size; } 385 void set_code_size(int size) { 386 assert(max_method_code_size < (1 << 16), 387 "u2 is too small to hold method code size in general"); 388 assert(0 <= size && size <= max_method_code_size, "invalid code size"); 389 _code_size = size; 390 } 391 392 // linenumber table - note that length is unknown until decompression, 393 // see class CompressedLineNumberReadStream. 394 u_char* compressed_linenumber_table() const; // not preserved by gc 395 u2* generic_signature_index_addr() const; 396 u2* checked_exceptions_length_addr() const; 397 u2* localvariable_table_length_addr() const; 398 u2* exception_table_length_addr() const; 399 u2* method_parameters_length_addr() const; 400 401 // checked exceptions 402 int checked_exceptions_length() const; 403 CheckedExceptionElement* checked_exceptions_start() const; 404 405 // localvariable table 406 int localvariable_table_length() const; 407 LocalVariableTableElement* localvariable_table_start() const; 408 409 // exception table 410 int exception_table_length() const; 411 ExceptionTableElement* exception_table_start() const; 412 413 // method parameters table 414 415 // This returns -1 if no parameters are present, a non-negative 416 // value otherwise. Note: sometimes, there are 0-length parameters 417 // attributes that must be reported up to the reflection API all the 418 // same. 419 int method_parameters_length() const; 420 MethodParametersElement* method_parameters_start() const; 421 422 // method annotations 423 bool has_method_annotations() const 424 { return (_flags & _has_method_annotations) != 0; } 425 426 bool has_parameter_annotations() const 427 { return (_flags & _has_parameter_annotations) != 0; } 428 429 bool has_type_annotations() const 430 { return (_flags & _has_type_annotations) != 0; } 431 432 bool has_default_annotations() const 433 { return (_flags & _has_default_annotations) != 0; } 434 435 436 AnnotationArray** method_annotations_addr() const; 437 AnnotationArray* method_annotations() const { 438 return has_method_annotations() ? *(method_annotations_addr()) : NULL; 439 } 440 void set_method_annotations(AnnotationArray* anno) { 441 *(method_annotations_addr()) = anno; 442 } 443 444 AnnotationArray** parameter_annotations_addr() const; 445 AnnotationArray* parameter_annotations() const { 446 return has_parameter_annotations() ? *(parameter_annotations_addr()) : NULL; 447 } 448 void set_parameter_annotations(AnnotationArray* anno) { 449 *(parameter_annotations_addr()) = anno; 450 } 451 452 AnnotationArray** type_annotations_addr() const; 453 AnnotationArray* type_annotations() const { 454 return has_type_annotations() ? *(type_annotations_addr()) : NULL; 455 } 456 void set_type_annotations(AnnotationArray* anno) { 457 *(type_annotations_addr()) = anno; 458 } 459 460 AnnotationArray** default_annotations_addr() const; 461 AnnotationArray* default_annotations() const { 462 return has_default_annotations() ? *(default_annotations_addr()) : NULL; 463 } 464 void set_default_annotations(AnnotationArray* anno) { 465 *(default_annotations_addr()) = anno; 466 } 467 468 int method_annotations_length() const { 469 return has_method_annotations() ? method_annotations()->length() : 0; 470 } 471 int parameter_annotations_length() const { 472 return has_parameter_annotations() ? parameter_annotations()->length() : 0; 473 } 474 int type_annotations_length() const { 475 return has_type_annotations() ? type_annotations()->length() : 0; 476 } 477 int default_annotations_length() const { 478 return has_default_annotations() ? default_annotations()->length() : 0; 479 } 480 481 // Copy annotations from other ConstMethod 482 void copy_annotations_from(ClassLoaderData* loader_data, ConstMethod* cm, TRAPS); 483 484 // byte codes 485 void set_code(address code) { 486 if (code_size() > 0) { 487 memcpy(code_base(), code, code_size()); 488 } 489 } 490 address code_base() const { return (address) (this+1); } 491 address code_end() const { return code_base() + code_size(); } 492 bool contains(address bcp) const { return code_base() <= bcp 493 && bcp < code_end(); } 494 // Offset to bytecodes 495 static ByteSize codes_offset() 496 { return in_ByteSize(sizeof(ConstMethod)); } 497 498 static ByteSize constants_offset() 499 { return byte_offset_of(ConstMethod, _constants); } 500 501 static ByteSize max_stack_offset() 502 { return byte_offset_of(ConstMethod, _max_stack); } 503 static ByteSize size_of_locals_offset() 504 { return byte_offset_of(ConstMethod, _max_locals); } 505 static ByteSize size_of_parameters_offset() 506 { return byte_offset_of(ConstMethod, _size_of_parameters); } 507 508 static ByteSize result_type_offset() 509 { return byte_offset_of(ConstMethod, _result_type); } 510 511 // Unique id for the method 512 static const u2 MAX_IDNUM; 513 static const u2 UNSET_IDNUM; 514 u2 method_idnum() const { return _method_idnum; } 515 void set_method_idnum(u2 idnum) { _method_idnum = idnum; } 516 517 u2 orig_method_idnum() const { return _orig_method_idnum; } 518 void set_orig_method_idnum(u2 idnum) { _orig_method_idnum = idnum; } 519 520 // max stack 521 int max_stack() const { return _max_stack; } 522 void set_max_stack(int size) { _max_stack = size; } 523 524 // max locals 525 int max_locals() const { return _max_locals; } 526 void set_max_locals(int size) { _max_locals = size; } 527 528 // size of parameters 529 int size_of_parameters() const { return _size_of_parameters; } 530 void set_size_of_parameters(int size) { _size_of_parameters = size; } 531 532 void set_result_type(BasicType rt) { assert(rt < 16, "result type too large"); 533 _result_type = (u1)rt; } 534 // Deallocation for RedefineClasses 535 void deallocate_contents(ClassLoaderData* loader_data); 536 bool is_klass() const { return false; } 537 DEBUG_ONLY(bool on_stack() { return false; }) 538 539 void metaspace_pointers_do(MetaspaceClosure* it); 540 MetaspaceObj::Type type() const { return ConstMethodType; } 541private: 542 // Since the size of the compressed line number table is unknown, the 543 // offsets of the other variable sized sections are computed backwards 544 // from the end of the ConstMethod*. 545 546 // First byte after ConstMethod* 547 address constMethod_end() const 548 { return (address)((intptr_t*)this + _constMethod_size); } 549 550 // Last short in ConstMethod* 551 u2* last_u2_element() const; 552 553 public: 554 // Printing 555 void print_on (outputStream* st) const; 556 void print_value_on(outputStream* st) const; 557 558 const char* internal_name() const { return "{constMethod}"; } 559 560 // Verify 561 void verify_on(outputStream* st); 562}; 563 564#endif // SHARE_VM_OOPS_CONSTMETHODOOP_HPP 565