1 /* 2 * Copyright (c) 1998, 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_CPCACHEOOP_HPP 26 #define SHARE_VM_OOPS_CPCACHEOOP_HPP 27 28 #include "interpreter/bytecodes.hpp" 29 #include "memory/allocation.hpp" 30 #include "oops/array.hpp" 31 #include "runtime/orderAccess.hpp" 32 #include "utilities/align.hpp" 33 34 class PSPromotionManager; 35 36 // The ConstantPoolCache is not a cache! It is the resolution table that the 37 // interpreter uses to avoid going into the runtime and a way to access resolved 38 // values. 39 40 // A ConstantPoolCacheEntry describes an individual entry of the constant 41 // pool cache. There's 2 principal kinds of entries: field entries for in- 42 // stance & static field access, and method entries for invokes. Some of 43 // the entry layout is shared and looks as follows: 44 // 45 // bit number |31 0| 46 // bit length |-8--|-8--|---16----| 47 // -------------------------------- 48 // _indices [ b2 | b1 | index ] index = constant_pool_index 49 // _f1 [ entry specific ] metadata ptr (method or klass) 50 // _f2 [ entry specific ] vtable or res_ref index, or vfinal method ptr 51 // _flags [tos|0|F=1|0|0|0|f|v|0 |0000|field_index] (for field entries) 52 // bit length [ 4 |1| 1 |1|1|1|1|1|1 |-4--|----16-----] 53 // _flags [tos|0|F=0|M|A|I|f|0|vf|0000|00000|psize] (for method entries) 54 // bit length [ 4 |1| 1 |1|1|1|1|1|1 |-4--|--8--|--8--] 55 56 // -------------------------------- 57 // 58 // with: 59 // index = original constant pool index 60 // b1 = bytecode 1 61 // b2 = bytecode 2 62 // psize = parameters size (method entries only) 63 // field_index = index into field information in holder InstanceKlass 64 // The index max is 0xffff (max number of fields in constant pool) 65 // and is multiplied by (InstanceKlass::next_offset) when accessing. 66 // tos = TosState 67 // F = the entry is for a field (or F=0 for a method) 68 // A = call site has an appendix argument (loaded from resolved references) 69 // I = interface call is forced virtual (must use a vtable index or vfinal) 70 // f = field or method is final 71 // v = field is volatile 72 // vf = virtual but final (method entries only: is_vfinal()) 73 // 74 // The flags after TosState have the following interpretation: 75 // bit 27: 0 for fields, 1 for methods 76 // f flag true if field is marked final 77 // v flag true if field is volatile (only for fields) 78 // f2 flag true if f2 contains an oop (e.g., virtual final method) 79 // fv flag true if invokeinterface used for method in class Object 80 // 81 // The flags 31, 30, 29, 28 together build a 4 bit number 0 to 16 with the 82 // following mapping to the TosState states: 83 // 84 // btos: 0 85 // ztos: 1 86 // ctos: 2 87 // stos: 3 88 // itos: 4 89 // ltos: 5 90 // ftos: 6 91 // dtos: 7 92 // atos: 8 93 // vtos: 9 94 // 95 // Entry specific: field entries: 96 // _indices = get (b1 section) and put (b2 section) bytecodes, original constant pool index 97 // _f1 = field holder (as a java.lang.Class, not a Klass*) 98 // _f2 = field offset in bytes 99 // _flags = field type information, original FieldInfo index in field holder 100 // (field_index section) 101 // 102 // Entry specific: method entries: 103 // _indices = invoke code for f1 (b1 section), invoke code for f2 (b2 section), 104 // original constant pool index 105 // _f1 = Method* for non-virtual calls, unused by virtual calls. 106 // for interface calls, which are essentially virtual but need a klass, 107 // contains Klass* for the corresponding interface. 108 // for invokedynamic and invokehandle, f1 contains the adapter method which 109 // manages the actual call. The appendix is stored in the ConstantPool 110 // resolved_references array. 111 // (upcoming metadata changes will move the appendix to a separate array) 112 // _f2 = vtable/itable index (or final Method*) for virtual calls only, 113 // unused by non-virtual. The is_vfinal flag indicates this is a 114 // method pointer for a final method, not an index. 115 // _flags = method type info (t section), 116 // virtual final bit (vfinal), 117 // parameter size (psize section) 118 // 119 // Note: invokevirtual & invokespecial bytecodes can share the same constant 120 // pool entry and thus the same constant pool cache entry. All invoke 121 // bytecodes but invokevirtual use only _f1 and the corresponding b1 122 // bytecode, while invokevirtual uses only _f2 and the corresponding 123 // b2 bytecode. The value of _flags is shared for both types of entries. 124 // 125 // The fields are volatile so that they are stored in the order written in the 126 // source code. The _indices field with the bytecode must be written last. 127 128 class CallInfo; 129 130 class ConstantPoolCacheEntry VALUE_OBJ_CLASS_SPEC { 131 friend class VMStructs; 132 friend class constantPoolCacheKlass; 133 friend class ConstantPool; 134 friend class InterpreterRuntime; 135 136 private: 137 volatile intx _indices; // constant pool index & rewrite bytecodes 138 volatile Metadata* _f1; // entry specific metadata field 139 volatile intx _f2; // entry specific int/metadata field 140 volatile intx _flags; // flags 141 142 143 void set_bytecode_1(Bytecodes::Code code); 144 void set_bytecode_2(Bytecodes::Code code); 145 void set_f1(Metadata* f1) { 146 Metadata* existing_f1 = (Metadata*)_f1; // read once 147 assert(existing_f1 == NULL || existing_f1 == f1, "illegal field change"); 148 _f1 = f1; 149 } 150 void release_set_f1(Metadata* f1); 151 void set_f2(intx f2) { 152 intx existing_f2 = _f2; // read once 153 assert(existing_f2 == 0 || existing_f2 == f2, "illegal field change"); 154 _f2 = f2; 155 } 156 void set_f2_as_vfinal_method(Method* f2) { 157 assert(is_vfinal(), "flags must be set"); 158 set_f2((intx)f2); 159 } 160 int make_flags(TosState state, int option_bits, int field_index_or_method_params); 161 void set_flags(intx flags) { _flags = flags; } 162 bool init_flags_atomic(intx flags); 163 void set_field_flags(TosState field_type, int option_bits, int field_index) { 164 assert((field_index & field_index_mask) == field_index, "field_index in range"); 165 set_flags(make_flags(field_type, option_bits | (1 << is_field_entry_shift), field_index)); 166 } 167 void set_method_flags(TosState return_type, int option_bits, int method_params) { 168 assert((method_params & parameter_size_mask) == method_params, "method_params in range"); 169 set_flags(make_flags(return_type, option_bits, method_params)); 170 } 171 bool init_method_flags_atomic(TosState return_type, int option_bits, int method_params) { 172 assert((method_params & parameter_size_mask) == method_params, "method_params in range"); 173 return init_flags_atomic(make_flags(return_type, option_bits, method_params)); 174 } 175 176 public: 177 // specific bit definitions for the flags field: 178 // (Note: the interpreter must use these definitions to access the CP cache.) 179 enum { 180 // high order bits are the TosState corresponding to field type or method return type 181 tos_state_bits = 4, 182 tos_state_mask = right_n_bits(tos_state_bits), 183 tos_state_shift = BitsPerInt - tos_state_bits, // see verify_tos_state_shift below 184 // misc. option bits; can be any bit position in [16..27] 185 is_field_entry_shift = 26, // (F) is it a field or a method? 186 has_method_type_shift = 25, // (M) does the call site have a MethodType? 187 has_appendix_shift = 24, // (A) does the call site have an appendix argument? 188 is_forced_virtual_shift = 23, // (I) is the interface reference forced to virtual mode? 189 is_final_shift = 22, // (f) is the field or method final? 190 is_volatile_shift = 21, // (v) is the field volatile? 191 is_vfinal_shift = 20, // (vf) did the call resolve to a final method? 192 // low order bits give field index (for FieldInfo) or method parameter size: 193 field_index_bits = 16, 194 field_index_mask = right_n_bits(field_index_bits), 195 parameter_size_bits = 8, // subset of field_index_mask, range is 0..255 196 parameter_size_mask = right_n_bits(parameter_size_bits), 197 option_bits_mask = ~(((~0u) << tos_state_shift) | (field_index_mask | parameter_size_mask)) 198 }; 199 200 // specific bit definitions for the indices field: 201 enum { 202 cp_index_bits = 2*BitsPerByte, 203 cp_index_mask = right_n_bits(cp_index_bits), 204 bytecode_1_shift = cp_index_bits, 205 bytecode_1_mask = right_n_bits(BitsPerByte), // == (u1)0xFF 206 bytecode_2_shift = cp_index_bits + BitsPerByte, 207 bytecode_2_mask = right_n_bits(BitsPerByte) // == (u1)0xFF 208 }; 209 210 211 // Initialization 212 void initialize_entry(int original_index); // initialize primary entry 213 void initialize_resolved_reference_index(int ref_index) { 214 assert(_f2 == 0, "set once"); // note: ref_index might be zero also 215 _f2 = ref_index; 216 } 217 218 void set_field( // sets entry to resolved field state 219 Bytecodes::Code get_code, // the bytecode used for reading the field 220 Bytecodes::Code put_code, // the bytecode used for writing the field 221 Klass* field_holder, // the object/klass holding the field 222 int orig_field_index, // the original field index in the field holder 223 int field_offset, // the field offset in words in the field holder 224 TosState field_type, // the (machine) field type 225 bool is_final, // the field is final 226 bool is_volatile, // the field is volatile 227 Klass* root_klass // needed by the GC to dirty the klass 228 ); 229 230 private: 231 void set_direct_or_vtable_call( 232 Bytecodes::Code invoke_code, // the bytecode used for invoking the method 233 const methodHandle& method, // the method/prototype if any (NULL, otherwise) 234 int vtable_index, // the vtable index if any, else negative 235 bool sender_is_interface 236 ); 237 238 public: 239 void set_direct_call( // sets entry to exact concrete method entry 240 Bytecodes::Code invoke_code, // the bytecode used for invoking the method 241 const methodHandle& method, // the method to call 242 bool sender_is_interface 243 ); 244 245 void set_vtable_call( // sets entry to vtable index 246 Bytecodes::Code invoke_code, // the bytecode used for invoking the method 247 const methodHandle& method, // resolved method which declares the vtable index 248 int vtable_index // the vtable index 249 ); 250 251 void set_itable_call( 252 Bytecodes::Code invoke_code, // the bytecode used; must be invokeinterface 253 const methodHandle& method, // the resolved interface method 254 int itable_index // index into itable for the method 255 ); 256 257 void set_method_handle( 258 const constantPoolHandle& cpool, // holding constant pool (required for locking) 259 const CallInfo &call_info // Call link information 260 ); 261 262 void set_dynamic_call( 263 const constantPoolHandle& cpool, // holding constant pool (required for locking) 264 const CallInfo &call_info // Call link information 265 ); 266 267 // Common code for invokedynamic and MH invocations. 268 269 // The "appendix" is an optional call-site-specific parameter which is 270 // pushed by the JVM at the end of the argument list. This argument may 271 // be a MethodType for the MH.invokes and a CallSite for an invokedynamic 272 // instruction. However, its exact type and use depends on the Java upcall, 273 // which simply returns a compiled LambdaForm along with any reference 274 // that LambdaForm needs to complete the call. If the upcall returns a 275 // null appendix, the argument is not passed at all. 276 // 277 // The appendix is *not* represented in the signature of the symbolic 278 // reference for the call site, but (if present) it *is* represented in 279 // the Method* bound to the site. This means that static and dynamic 280 // resolution logic needs to make slightly different assessments about the 281 // number and types of arguments. 282 void set_method_handle_common( 283 const constantPoolHandle& cpool, // holding constant pool (required for locking) 284 Bytecodes::Code invoke_code, // _invokehandle or _invokedynamic 285 const CallInfo &call_info // Call link information 286 ); 287 288 // invokedynamic and invokehandle call sites have two entries in the 289 // resolved references array: 290 // appendix (at index+0) 291 // MethodType (at index+1) 292 enum { 293 _indy_resolved_references_appendix_offset = 0, 294 _indy_resolved_references_method_type_offset = 1, 295 _indy_resolved_references_entries 296 }; 297 298 Method* method_if_resolved(const constantPoolHandle& cpool); 299 oop appendix_if_resolved(const constantPoolHandle& cpool); 300 oop method_type_if_resolved(const constantPoolHandle& cpool); 301 302 void set_parameter_size(int value); 303 304 // Which bytecode number (1 or 2) in the index field is valid for this bytecode? 305 // Returns -1 if neither is valid. 306 static int bytecode_number(Bytecodes::Code code) { 307 switch (code) { 308 case Bytecodes::_getstatic : // fall through 309 case Bytecodes::_getfield : // fall through 310 case Bytecodes::_invokespecial : // fall through 311 case Bytecodes::_invokestatic : // fall through 312 case Bytecodes::_invokehandle : // fall through 313 case Bytecodes::_invokedynamic : // fall through 314 case Bytecodes::_invokeinterface : return 1; 315 case Bytecodes::_putstatic : // fall through 316 case Bytecodes::_putfield : // fall through 317 case Bytecodes::_invokevirtual : return 2; 318 default : break; 319 } 320 return -1; 321 } 322 323 // Has this bytecode been resolved? Only valid for invokes and get/put field/static. 324 bool is_resolved(Bytecodes::Code code) const { 325 switch (bytecode_number(code)) { 326 case 1: return (bytecode_1() == code); 327 case 2: return (bytecode_2() == code); 328 } 329 return false; // default: not resolved 330 } 331 332 // Accessors 333 int indices() const { return _indices; } 334 int indices_ord() const { return (intx)OrderAccess::load_ptr_acquire(&_indices); } 335 int constant_pool_index() const { return (indices() & cp_index_mask); } 336 Bytecodes::Code bytecode_1() const { return Bytecodes::cast((indices_ord() >> bytecode_1_shift) & bytecode_1_mask); } 337 Bytecodes::Code bytecode_2() const { return Bytecodes::cast((indices_ord() >> bytecode_2_shift) & bytecode_2_mask); } 338 Metadata* f1_ord() const { return (Metadata *)OrderAccess::load_ptr_acquire(&_f1); } 339 Method* f1_as_method() const { Metadata* f1 = f1_ord(); assert(f1 == NULL || f1->is_method(), ""); return (Method*)f1; } 340 Klass* f1_as_klass() const { Metadata* f1 = f1_ord(); assert(f1 == NULL || f1->is_klass(), ""); return (Klass*)f1; } 341 // Use the accessor f1() to acquire _f1's value. This is needed for 342 // example in BytecodeInterpreter::run(), where is_f1_null() is 343 // called to check if an invokedynamic call is resolved. This load 344 // of _f1 must be ordered with the loads performed by 345 // cache->main_entry_index(). 346 bool is_f1_null() const { Metadata* f1 = f1_ord(); return f1 == NULL; } // classifies a CPC entry as unbound 347 int f2_as_index() const { assert(!is_vfinal(), ""); return (int) _f2; } 348 Method* f2_as_vfinal_method() const { assert(is_vfinal(), ""); return (Method*)_f2; } 349 int field_index() const { assert(is_field_entry(), ""); return (_flags & field_index_mask); } 350 int parameter_size() const { assert(is_method_entry(), ""); return (_flags & parameter_size_mask); } 351 bool is_volatile() const { return (_flags & (1 << is_volatile_shift)) != 0; } 352 bool is_final() const { return (_flags & (1 << is_final_shift)) != 0; } 353 bool is_forced_virtual() const { return (_flags & (1 << is_forced_virtual_shift)) != 0; } 354 bool is_vfinal() const { return (_flags & (1 << is_vfinal_shift)) != 0; } 355 bool has_appendix() const { return (!is_f1_null()) && (_flags & (1 << has_appendix_shift)) != 0; } 356 bool has_method_type() const { return (!is_f1_null()) && (_flags & (1 << has_method_type_shift)) != 0; } 357 bool is_method_entry() const { return (_flags & (1 << is_field_entry_shift)) == 0; } 358 bool is_field_entry() const { return (_flags & (1 << is_field_entry_shift)) != 0; } 359 bool is_long() const { return flag_state() == ltos; } 360 bool is_double() const { return flag_state() == dtos; } 361 TosState flag_state() const { assert((uint)number_of_states <= (uint)tos_state_mask+1, ""); 362 return (TosState)((_flags >> tos_state_shift) & tos_state_mask); } 363 364 // Code generation support 365 static WordSize size() { 366 return in_WordSize(align_up((int)sizeof(ConstantPoolCacheEntry), wordSize) / wordSize); 367 } 368 static ByteSize size_in_bytes() { return in_ByteSize(sizeof(ConstantPoolCacheEntry)); } 369 static ByteSize indices_offset() { return byte_offset_of(ConstantPoolCacheEntry, _indices); } 370 static ByteSize f1_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f1); } 371 static ByteSize f2_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f2); } 372 static ByteSize flags_offset() { return byte_offset_of(ConstantPoolCacheEntry, _flags); } 373 374 #if INCLUDE_JVMTI 375 // RedefineClasses() API support: 376 // If this ConstantPoolCacheEntry refers to old_method then update it 377 // to refer to new_method. 378 // trace_name_printed is set to true if the current call has 379 // printed the klass name so that other routines in the adjust_* 380 // group don't print the klass name. 381 bool adjust_method_entry(Method* old_method, Method* new_method, 382 bool* trace_name_printed); 383 bool check_no_old_or_obsolete_entries(); 384 Method* get_interesting_method_entry(Klass* k); 385 #endif // INCLUDE_JVMTI 386 387 // Debugging & Printing 388 void print (outputStream* st, int index) const; 389 void verify(outputStream* st) const; 390 391 static void verify_tos_state_shift() { 392 // When shifting flags as a 32-bit int, make sure we don't need an extra mask for tos_state: 393 assert((((u4)-1 >> tos_state_shift) & ~tos_state_mask) == 0, "no need for tos_state mask"); 394 } 395 }; 396 397 398 // A constant pool cache is a runtime data structure set aside to a constant pool. The cache 399 // holds interpreter runtime information for all field access and invoke bytecodes. The cache 400 // is created and initialized before a class is actively used (i.e., initialized), the indivi- 401 // dual cache entries are filled at resolution (i.e., "link") time (see also: rewriter.*). 402 403 class ConstantPoolCache: public MetaspaceObj { 404 friend class VMStructs; 405 friend class MetadataFactory; 406 private: 407 // If you add a new field that points to any metaspace object, you 408 // must add this field to ConstantPoolCache::metaspace_pointers_do(). 409 int _length; 410 ConstantPool* _constant_pool; // the corresponding constant pool 411 412 // The following fields need to be modified at runtime, so they cannot be 413 // stored in the ConstantPool, which is read-only. 414 // Array of resolved objects from the constant pool and map from resolved 415 // object index to original constant pool index 416 jobject _resolved_references; 417 Array<u2>* _reference_map; 418 419 // Sizing 420 debug_only(friend class ClassVerifier;) 421 422 // Constructor 423 ConstantPoolCache(int length, 424 const intStack& inverse_index_map, 425 const intStack& invokedynamic_inverse_index_map, 426 const intStack& invokedynamic_references_map) : 427 _length(length), 428 _constant_pool(NULL) { 429 initialize(inverse_index_map, invokedynamic_inverse_index_map, 430 invokedynamic_references_map); 431 for (int i = 0; i < length; i++) { 432 assert(entry_at(i)->is_f1_null(), "Failed to clear?"); 433 } 434 } 435 436 // Initialization 437 void initialize(const intArray& inverse_index_map, 438 const intArray& invokedynamic_inverse_index_map, 439 const intArray& invokedynamic_references_map); 440 public: 441 static ConstantPoolCache* allocate(ClassLoaderData* loader_data, 442 const intStack& cp_cache_map, 443 const intStack& invokedynamic_cp_cache_map, 444 const intStack& invokedynamic_references_map, TRAPS); 445 bool is_constantPoolCache() const { return true; } 446 447 int length() const { return _length; } 448 void metaspace_pointers_do(MetaspaceClosure* it); 449 MetaspaceObj::Type type() const { return ConstantPoolCacheType; } 450 451 jobject resolved_references() { return _resolved_references; } 452 void set_resolved_references(jobject s) { _resolved_references = s; } 453 Array<u2>* reference_map() const { return _reference_map; } 454 void set_reference_map(Array<u2>* o) { _reference_map = o; } 455 456 // Assembly code support 457 static int resolved_references_offset_in_bytes() { return offset_of(ConstantPoolCache, _resolved_references); } 458 459 private: 460 void set_length(int length) { _length = length; } 461 462 static int header_size() { return sizeof(ConstantPoolCache) / wordSize; } 463 static int size(int length) { return align_metadata_size(header_size() + length * in_words(ConstantPoolCacheEntry::size())); } 464 public: 465 int size() const { return size(length()); } 466 private: 467 468 // Helpers 469 ConstantPool** constant_pool_addr() { return &_constant_pool; } 470 ConstantPoolCacheEntry* base() const { return (ConstantPoolCacheEntry*)((address)this + in_bytes(base_offset())); } 471 472 friend class constantPoolCacheKlass; 473 friend class ConstantPoolCacheEntry; 474 475 public: 476 // Accessors 477 void set_constant_pool(ConstantPool* pool) { _constant_pool = pool; } 478 ConstantPool* constant_pool() const { return _constant_pool; } 479 // Fetches the entry at the given index. 480 // In either case the index must not be encoded or byte-swapped in any way. 481 ConstantPoolCacheEntry* entry_at(int i) const { 482 assert(0 <= i && i < length(), "index out of bounds"); 483 return base() + i; 484 } 485 486 // Code generation 487 static ByteSize base_offset() { return in_ByteSize(sizeof(ConstantPoolCache)); } 488 static ByteSize entry_offset(int raw_index) { 489 int index = raw_index; 490 return (base_offset() + ConstantPoolCacheEntry::size_in_bytes() * index); 491 } 492 493 #if INCLUDE_JVMTI 494 // RedefineClasses() API support: 495 // If any entry of this ConstantPoolCache points to any of 496 // old_methods, replace it with the corresponding new_method. 497 // trace_name_printed is set to true if the current call has 498 // printed the klass name so that other routines in the adjust_* 499 // group don't print the klass name. 500 void adjust_method_entries(InstanceKlass* holder, bool* trace_name_printed); 501 bool check_no_old_or_obsolete_entries(); 502 void dump_cache(); 503 #endif // INCLUDE_JVMTI 504 505 // Deallocate - no fields to deallocate 506 DEBUG_ONLY(bool on_stack() { return false; }) 507 void deallocate_contents(ClassLoaderData* data) {} 508 bool is_klass() const { return false; } 509 510 // Printing 511 void print_on(outputStream* st) const; 512 void print_value_on(outputStream* st) const; 513 514 const char* internal_name() const { return "{constant pool cache}"; } 515 516 // Verify 517 void verify_on(outputStream* st); 518 }; 519 520 #endif // SHARE_VM_OOPS_CPCACHEOOP_HPP