1 /* 2 * Copyright (c) 2003, 2018, 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*. 91 class CheckedExceptionElement { 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 { 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 { 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 { 119 public: 120 u2 name_cp_index; 121 u2 flags; 122 }; 123 124 class KlassSizeStats; 125 class 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; } 145 146 class InlineTableSizes : StackObj { 147 // declarations 148 INLINE_TABLES_DO(INLINE_TABLE_DECLARE) 149 int _end; 150 public: InlineTableSizes(INLINE_TABLES_DO (INLINE_TABLE_PARAM)int end)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 InlineTableSizes()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 170 171 class ConstMethod : public MetaspaceObj { 172 friend class VMStructs; 173 friend class JVMCIVMStructs; 174 175 public: 176 typedef enum { NORMAL, OVERPASS } MethodType; 177 178 private: 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); 236 public: 237 238 static ConstMethod* allocate(ClassLoaderData* loader_data, 239 int byte_code_size, 240 InlineTableSizes* sizes, 241 MethodType mt, 242 TRAPS); 243 is_constMethod() const244 bool is_constMethod() const { return true; } 245 246 // Inlined tables 247 void set_inlined_tables_length(InlineTableSizes* sizes); 248 has_generic_signature() const249 bool has_generic_signature() const 250 { return (_flags & _has_generic_signature) != 0; } 251 has_linenumber_table() const252 bool has_linenumber_table() const 253 { return (_flags & _has_linenumber_table) != 0; } 254 has_checked_exceptions() const255 bool has_checked_exceptions() const 256 { return (_flags & _has_checked_exceptions) != 0; } 257 has_localvariable_table() const258 bool has_localvariable_table() const 259 { return (_flags & _has_localvariable_table) != 0; } 260 has_exception_handler() const261 bool has_exception_handler() const 262 { return (_flags & _has_exception_table) != 0; } 263 has_method_parameters() const264 bool has_method_parameters() const 265 { return (_flags & _has_method_parameters) != 0; } 266 method_type() const267 MethodType method_type() const { 268 return ((_flags & _is_overpass) == 0) ? NORMAL : OVERPASS; 269 } 270 set_method_type(MethodType mt)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 constants() const280 ConstantPool* constants() const { return _constants; } set_constants(ConstantPool * c)281 void set_constants(ConstantPool* c) { _constants = c; } 282 283 Method* method() const; 284 285 // stackmap table data stackmap_data() const286 Array<u1>* stackmap_data() const { return _stackmap_data; } set_stackmap_data(Array<u1> * sd)287 void set_stackmap_data(Array<u1>* sd) { _stackmap_data = sd; } 288 void copy_stackmap_data(ClassLoaderData* loader_data, u1* sd, int length, TRAPS); has_stackmap_table() const289 bool has_stackmap_table() const { return _stackmap_data != NULL; } 290 291 // adapter set_adapter_entry(AdapterHandlerEntry * adapter)292 void set_adapter_entry(AdapterHandlerEntry* adapter) { 293 assert(!is_shared(), "shared methods have fixed adapter_trampoline"); 294 _adapter = adapter; 295 } set_adapter_trampoline(AdapterHandlerEntry ** trampoline)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 } update_adapter_trampoline(AdapterHandlerEntry * adapter)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 } adapter()306 AdapterHandlerEntry* adapter() { 307 if (is_shared()) { 308 return *_adapter_trampoline; 309 } else { 310 return _adapter; 311 } 312 } 313 init_fingerprint()314 void init_fingerprint() { 315 const uint64_t initval = UCONST64(0x8000000000000000); 316 _fingerprint = initval; 317 } 318 fingerprint() const319 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 set_fingerprint(uint64_t new_fingerprint)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 name_index() const344 int name_index() const { return _name_index; } set_name_index(int index)345 void set_name_index(int index) { _name_index = index; } 346 347 // signature signature_index() const348 int signature_index() const { return _signature_index; } set_signature_index(int index)349 void set_signature_index(int index) { _signature_index = index; } 350 351 // generics support generic_signature_index() const352 int generic_signature_index() const { 353 if (has_generic_signature()) { 354 return *generic_signature_index_addr(); 355 } else { 356 return 0; 357 } 358 } set_generic_signature_index(u2 index)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 header_size()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 size() const373 int size() const { return _constMethod_size;} set_constMethod_size(int 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. is_read_only_by_default()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 code_size() const384 int code_size() const { return _code_size; } set_code_size(int 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 has_method_annotations() const423 bool has_method_annotations() const 424 { return (_flags & _has_method_annotations) != 0; } 425 has_parameter_annotations() const426 bool has_parameter_annotations() const 427 { return (_flags & _has_parameter_annotations) != 0; } 428 has_type_annotations() const429 bool has_type_annotations() const 430 { return (_flags & _has_type_annotations) != 0; } 431 has_default_annotations() const432 bool has_default_annotations() const 433 { return (_flags & _has_default_annotations) != 0; } 434 435 436 AnnotationArray** method_annotations_addr() const; method_annotations() const437 AnnotationArray* method_annotations() const { 438 return has_method_annotations() ? *(method_annotations_addr()) : NULL; 439 } set_method_annotations(AnnotationArray * anno)440 void set_method_annotations(AnnotationArray* anno) { 441 *(method_annotations_addr()) = anno; 442 } 443 444 AnnotationArray** parameter_annotations_addr() const; parameter_annotations() const445 AnnotationArray* parameter_annotations() const { 446 return has_parameter_annotations() ? *(parameter_annotations_addr()) : NULL; 447 } set_parameter_annotations(AnnotationArray * anno)448 void set_parameter_annotations(AnnotationArray* anno) { 449 *(parameter_annotations_addr()) = anno; 450 } 451 452 AnnotationArray** type_annotations_addr() const; type_annotations() const453 AnnotationArray* type_annotations() const { 454 return has_type_annotations() ? *(type_annotations_addr()) : NULL; 455 } set_type_annotations(AnnotationArray * anno)456 void set_type_annotations(AnnotationArray* anno) { 457 *(type_annotations_addr()) = anno; 458 } 459 460 AnnotationArray** default_annotations_addr() const; default_annotations() const461 AnnotationArray* default_annotations() const { 462 return has_default_annotations() ? *(default_annotations_addr()) : NULL; 463 } set_default_annotations(AnnotationArray * anno)464 void set_default_annotations(AnnotationArray* anno) { 465 *(default_annotations_addr()) = anno; 466 } 467 method_annotations_length() const468 int method_annotations_length() const { 469 return has_method_annotations() ? method_annotations()->length() : 0; 470 } parameter_annotations_length() const471 int parameter_annotations_length() const { 472 return has_parameter_annotations() ? parameter_annotations()->length() : 0; 473 } type_annotations_length() const474 int type_annotations_length() const { 475 return has_type_annotations() ? type_annotations()->length() : 0; 476 } default_annotations_length() const477 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 set_code(address code)485 void set_code(address code) { 486 if (code_size() > 0) { 487 memcpy(code_base(), code, code_size()); 488 } 489 } code_base() const490 address code_base() const { return (address) (this+1); } code_end() const491 address code_end() const { return code_base() + code_size(); } contains(address bcp) const492 bool contains(address bcp) const { return code_base() <= bcp 493 && bcp < code_end(); } 494 // Offset to bytecodes codes_offset()495 static ByteSize codes_offset() 496 { return in_ByteSize(sizeof(ConstMethod)); } 497 constants_offset()498 static ByteSize constants_offset() 499 { return byte_offset_of(ConstMethod, _constants); } 500 max_stack_offset()501 static ByteSize max_stack_offset() 502 { return byte_offset_of(ConstMethod, _max_stack); } size_of_locals_offset()503 static ByteSize size_of_locals_offset() 504 { return byte_offset_of(ConstMethod, _max_locals); } size_of_parameters_offset()505 static ByteSize size_of_parameters_offset() 506 { return byte_offset_of(ConstMethod, _size_of_parameters); } 507 result_type_offset()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; method_idnum() const514 u2 method_idnum() const { return _method_idnum; } set_method_idnum(u2 idnum)515 void set_method_idnum(u2 idnum) { _method_idnum = idnum; } 516 orig_method_idnum() const517 u2 orig_method_idnum() const { return _orig_method_idnum; } set_orig_method_idnum(u2 idnum)518 void set_orig_method_idnum(u2 idnum) { _orig_method_idnum = idnum; } 519 520 // max stack max_stack() const521 int max_stack() const { return _max_stack; } set_max_stack(int size)522 void set_max_stack(int size) { _max_stack = size; } 523 524 // max locals max_locals() const525 int max_locals() const { return _max_locals; } set_max_locals(int size)526 void set_max_locals(int size) { _max_locals = size; } 527 528 // size of parameters size_of_parameters() const529 int size_of_parameters() const { return _size_of_parameters; } set_size_of_parameters(int size)530 void set_size_of_parameters(int size) { _size_of_parameters = size; } 531 set_result_type(BasicType rt)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); is_klass() const536 bool is_klass() const { return false; } 537 DEBUG_ONLY(bool on_stack() { return false; }) 538 539 void metaspace_pointers_do(MetaspaceClosure* it); type() const540 MetaspaceObj::Type type() const { return ConstMethodType; } 541 private: 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* constMethod_end() const547 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 internal_name() const558 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