1 /* 2 * Copyright (c) 1998, 2020, 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_OOPS_CPCACHE_HPP 26 #define SHARE_OOPS_CPCACHE_HPP 27 28 #include "interpreter/bytecodes.hpp" 29 #include "memory/allocation.hpp" 30 #include "oops/array.hpp" 31 #include "oops/oopHandle.hpp" 32 #include "runtime/handles.hpp" 33 #include "utilities/align.hpp" 34 #include "utilities/constantTag.hpp" 35 #include "utilities/growableArray.hpp" 36 37 class PSPromotionManager; 38 39 // The ConstantPoolCache is not a cache! It is the resolution table that the 40 // interpreter uses to avoid going into the runtime and a way to access resolved 41 // values. 42 43 // A ConstantPoolCacheEntry describes an individual entry of the constant 44 // pool cache. There's 2 principal kinds of entries: field entries for in- 45 // stance & static field access, and method entries for invokes. Some of 46 // the entry layout is shared and looks as follows: 47 // 48 // bit number |31 0| 49 // bit length |-8--|-8--|---16----| 50 // -------------------------------- 51 // _indices [ b2 | b1 | index ] index = constant_pool_index 52 // _f1 [ entry specific ] metadata ptr (method or klass) 53 // _f2 [ entry specific ] vtable or res_ref index, or vfinal method ptr 54 // _flags [tos|0|F=1|0|0|0|f|v|0 |0000|field_index] (for field entries) 55 // bit length [ 4 |1| 1 |1|1|1|1|1|1 |1 |-3-|----16-----] 56 // _flags [tos|0|F=0|S|A|I|f|0|vf|indy_rf|000|00000|psize] (for method entries) 57 // bit length [ 4 |1| 1 |1|1|1|1|1|1 |-4--|--8--|--8--] 58 59 // -------------------------------- 60 // 61 // with: 62 // index = original constant pool index 63 // b1 = bytecode 1 64 // b2 = bytecode 2 65 // psize = parameters size (method entries only) 66 // field_index = index into field information in holder InstanceKlass 67 // The index max is 0xffff (max number of fields in constant pool) 68 // and is multiplied by (InstanceKlass::next_offset) when accessing. 69 // tos = TosState 70 // F = the entry is for a field (or F=0 for a method) 71 // A = call site has an appendix argument (loaded from resolved references) 72 // I = interface call is forced virtual (must use a vtable index or vfinal) 73 // f = field or method is final 74 // v = field is volatile 75 // vf = virtual but final (method entries only: is_vfinal()) 76 // indy_rf = call site specifier method resolution failed 77 // 78 // The flags after TosState have the following interpretation: 79 // bit 27: 0 for fields, 1 for methods 80 // f flag true if field is marked final 81 // v flag true if field is volatile (only for fields) 82 // f2 flag true if f2 contains an oop (e.g., virtual final method) 83 // fv flag true if invokeinterface used for method in class Object 84 // 85 // The flags 31, 30, 29, 28 together build a 4 bit number 0 to 16 with the 86 // following mapping to the TosState states: 87 // 88 // btos: 0 89 // ztos: 1 90 // ctos: 2 91 // stos: 3 92 // itos: 4 93 // ltos: 5 94 // ftos: 6 95 // dtos: 7 96 // atos: 8 97 // vtos: 9 98 // 99 // Entry specific: field entries: 100 // _indices = get (b1 section) and put (b2 section) bytecodes, original constant pool index 101 // _f1 = field holder (as a java.lang.Class, not a Klass*) 102 // _f2 = field offset in bytes 103 // _flags = field type information, original FieldInfo index in field holder 104 // (field_index section) 105 // 106 // Entry specific: method entries: 107 // _indices = invoke code for f1 (b1 section), invoke code for f2 (b2 section), 108 // original constant pool index 109 // _f1 = Method* for non-virtual calls, unused by virtual calls. 110 // for interface calls, which are essentially virtual but need a klass, 111 // contains Klass* for the corresponding interface. 112 // for invokedynamic and invokehandle, f1 contains the adapter method which 113 // manages the actual call. The appendix is stored in the ConstantPool 114 // resolved_references array. 115 // (upcoming metadata changes will move the appendix to a separate array) 116 // _f2 = vtable/itable index (or final Method*) for virtual calls only, 117 // unused by non-virtual. The is_vfinal flag indicates this is a 118 // method pointer for a final method, not an index. 119 // _flags = has local signature (MHs and indy), 120 // virtual final bit (vfinal), 121 // parameter size (psize section) 122 // 123 // Note: invokevirtual & invokespecial bytecodes can share the same constant 124 // pool entry and thus the same constant pool cache entry. All invoke 125 // bytecodes but invokevirtual use only _f1 and the corresponding b1 126 // bytecode, while invokevirtual uses only _f2 and the corresponding 127 // b2 bytecode. The value of _flags is shared for both types of entries. 128 // 129 // The fields are volatile so that they are stored in the order written in the 130 // source code. The _indices field with the bytecode must be written last. 131 132 class CallInfo; 133 134 class ConstantPoolCacheEntry { 135 friend class VMStructs; 136 friend class constantPoolCacheKlass; 137 friend class ConstantPool; 138 friend class InterpreterRuntime; 139 140 private: 141 volatile intx _indices; // constant pool index & rewrite bytecodes 142 Metadata* volatile _f1; // entry specific metadata field 143 volatile intx _f2; // entry specific int/metadata field 144 volatile intx _flags; // flags 145 146 147 void set_bytecode_1(Bytecodes::Code code); 148 void set_bytecode_2(Bytecodes::Code code); set_f1(Metadata * f1)149 void set_f1(Metadata* f1) { 150 Metadata* existing_f1 = _f1; // read once 151 assert(existing_f1 == NULL || existing_f1 == f1, "illegal field change"); 152 _f1 = f1; 153 } 154 void release_set_f1(Metadata* f1); set_f2(intx f2)155 void set_f2(intx f2) { 156 intx existing_f2 = _f2; // read once 157 assert(existing_f2 == 0 || existing_f2 == f2, "illegal field change"); 158 _f2 = f2; 159 } set_f2_as_vfinal_method(Method * f2)160 void set_f2_as_vfinal_method(Method* f2) { 161 assert(is_vfinal(), "flags must be set"); 162 set_f2((intx)f2); 163 } 164 int make_flags(TosState state, int option_bits, int field_index_or_method_params); set_flags(intx flags)165 void set_flags(intx flags) { _flags = flags; } set_field_flags(TosState field_type,int option_bits,int field_index)166 void set_field_flags(TosState field_type, int option_bits, int field_index) { 167 assert((field_index & field_index_mask) == field_index, "field_index in range"); 168 set_flags(make_flags(field_type, option_bits | (1 << is_field_entry_shift), field_index)); 169 } set_method_flags(TosState return_type,int option_bits,int method_params)170 void set_method_flags(TosState return_type, int option_bits, int method_params) { 171 assert((method_params & parameter_size_mask) == method_params, "method_params in range"); 172 set_flags(make_flags(return_type, option_bits, method_params)); 173 } 174 175 public: 176 // specific bit definitions for the flags field: 177 // (Note: the interpreter must use these definitions to access the CP cache.) 178 enum { 179 // high order bits are the TosState corresponding to field type or method return type 180 tos_state_bits = 4, 181 tos_state_mask = right_n_bits(tos_state_bits), 182 tos_state_shift = BitsPerInt - tos_state_bits, // see verify_tos_state_shift below 183 // misc. option bits; can be any bit position in [16..27] 184 is_field_entry_shift = 26, // (F) is it a field or a method? 185 has_local_signature_shift = 25, // (S) does the call site have a per-site signature (sig-poly methods)? 186 has_appendix_shift = 24, // (A) does the call site have an appendix argument? 187 is_forced_virtual_shift = 23, // (I) is the interface reference forced to virtual mode? 188 is_final_shift = 22, // (f) is the field or method final? 189 is_volatile_shift = 21, // (v) is the field volatile? 190 is_vfinal_shift = 20, // (vf) did the call resolve to a final method? 191 indy_resolution_failed_shift= 19, // (indy_rf) did call site specifier resolution fail ? 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 initialize_resolved_reference_index(int ref_index)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 ); 228 229 private: 230 void set_direct_or_vtable_call( 231 Bytecodes::Code invoke_code, // the bytecode used for invoking the method 232 const methodHandle& method, // the method/prototype if any (NULL, otherwise) 233 int vtable_index, // the vtable index if any, else negative 234 bool sender_is_interface 235 ); 236 237 public: 238 void set_direct_call( // sets entry to exact concrete method entry 239 Bytecodes::Code invoke_code, // the bytecode used for invoking the method 240 const methodHandle& method, // the method to call 241 bool sender_is_interface 242 ); 243 244 void set_vtable_call( // sets entry to vtable index 245 Bytecodes::Code invoke_code, // the bytecode used for invoking the method 246 const methodHandle& method, // resolved method which declares the vtable index 247 int vtable_index // the vtable index 248 ); 249 250 void set_itable_call( 251 Bytecodes::Code invoke_code, // the bytecode used; must be invokeinterface 252 Klass* referenced_klass, // the referenced klass in the InterfaceMethodref 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 // Return TRUE if resolution failed and this thread got to record the failure 289 // status. Return FALSE if another thread succeeded or failed in resolving 290 // the method and recorded the success or failure before this thread had a 291 // chance to record its failure. 292 bool save_and_throw_indy_exc(const constantPoolHandle& cpool, int cpool_index, 293 int index, constantTag tag, TRAPS); 294 295 // invokedynamic and invokehandle call sites have an "appendix" item in the 296 // resolved references array. 297 Method* method_if_resolved(const constantPoolHandle& cpool); 298 oop appendix_if_resolved(const constantPoolHandle& cpool); 299 300 void set_parameter_size(int value); 301 302 // Which bytecode number (1 or 2) in the index field is valid for this bytecode? 303 // Returns -1 if neither is valid. bytecode_number(Bytecodes::Code code)304 static int bytecode_number(Bytecodes::Code code) { 305 switch (code) { 306 case Bytecodes::_getstatic : // fall through 307 case Bytecodes::_getfield : // fall through 308 case Bytecodes::_invokespecial : // fall through 309 case Bytecodes::_invokestatic : // fall through 310 case Bytecodes::_invokehandle : // fall through 311 case Bytecodes::_invokedynamic : // fall through 312 case Bytecodes::_invokeinterface : return 1; 313 case Bytecodes::_putstatic : // fall through 314 case Bytecodes::_putfield : // fall through 315 case Bytecodes::_invokevirtual : return 2; 316 default : break; 317 } 318 return -1; 319 } 320 321 // Has this bytecode been resolved? Only valid for invokes and get/put field/static. 322 bool is_resolved(Bytecodes::Code code) const; 323 324 // Accessors indices() const325 int indices() const { return _indices; } 326 int indices_ord() const; constant_pool_index() const327 int constant_pool_index() const { return (indices() & cp_index_mask); } 328 Bytecodes::Code bytecode_1() const; 329 Bytecodes::Code bytecode_2() const; 330 Metadata* f1_ord() const; 331 Method* f1_as_method() const; 332 Klass* f1_as_klass() const; 333 // Use the accessor f1() to acquire _f1's value. This is needed for 334 // example in BytecodeInterpreter::run(), where is_f1_null() is 335 // called to check if an invokedynamic call is resolved. This load 336 // of _f1 must be ordered with the loads performed by 337 // cache->main_entry_index(). 338 bool is_f1_null() const; // classifies a CPC entry as unbound f2_as_index() const339 int f2_as_index() const { assert(!is_vfinal(), ""); return (int) _f2; } f2_as_vfinal_method() const340 Method* f2_as_vfinal_method() const { assert(is_vfinal(), ""); return (Method*)_f2; } 341 Method* f2_as_interface_method() const; 342 intx flags_ord() const; field_index() const343 int field_index() const { assert(is_field_entry(), ""); return (_flags & field_index_mask); } parameter_size() const344 int parameter_size() const { assert(is_method_entry(), ""); return (_flags & parameter_size_mask); } is_volatile() const345 bool is_volatile() const { return (_flags & (1 << is_volatile_shift)) != 0; } is_final() const346 bool is_final() const { return (_flags & (1 << is_final_shift)) != 0; } is_forced_virtual() const347 bool is_forced_virtual() const { return (_flags & (1 << is_forced_virtual_shift)) != 0; } is_vfinal() const348 bool is_vfinal() const { return (_flags & (1 << is_vfinal_shift)) != 0; } 349 bool indy_resolution_failed() const; 350 bool has_appendix() const; 351 bool has_local_signature() const; is_method_entry() const352 bool is_method_entry() const { return (_flags & (1 << is_field_entry_shift)) == 0; } is_field_entry() const353 bool is_field_entry() const { return (_flags & (1 << is_field_entry_shift)) != 0; } is_long() const354 bool is_long() const { return flag_state() == ltos; } is_double() const355 bool is_double() const { return flag_state() == dtos; } flag_state() const356 TosState flag_state() const { assert((uint)number_of_states <= (uint)tos_state_mask+1, ""); 357 return (TosState)((_flags >> tos_state_shift) & tos_state_mask); } 358 void set_indy_resolution_failed(); 359 360 // Code generation support size()361 static WordSize size() { 362 return in_WordSize(align_up((int)sizeof(ConstantPoolCacheEntry), wordSize) / wordSize); 363 } size_in_bytes()364 static ByteSize size_in_bytes() { return in_ByteSize(sizeof(ConstantPoolCacheEntry)); } indices_offset()365 static ByteSize indices_offset() { return byte_offset_of(ConstantPoolCacheEntry, _indices); } f1_offset()366 static ByteSize f1_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f1); } f2_offset()367 static ByteSize f2_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f2); } flags_offset()368 static ByteSize flags_offset() { return byte_offset_of(ConstantPoolCacheEntry, _flags); } 369 370 #if INCLUDE_JVMTI 371 // RedefineClasses() API support: 372 // If this ConstantPoolCacheEntry refers to old_method then update it 373 // to refer to new_method. 374 // trace_name_printed is set to true if the current call has 375 // printed the klass name so that other routines in the adjust_* 376 // group don't print the klass name. 377 void adjust_method_entry(Method* old_method, Method* new_method, 378 bool* trace_name_printed); 379 bool check_no_old_or_obsolete_entries(); 380 Method* get_interesting_method_entry(); 381 #endif // INCLUDE_JVMTI 382 383 // Debugging & Printing 384 void print (outputStream* st, int index) const; 385 void verify(outputStream* st) const; 386 verify_tos_state_shift()387 static void verify_tos_state_shift() { 388 // When shifting flags as a 32-bit int, make sure we don't need an extra mask for tos_state: 389 assert((((u4)-1 >> tos_state_shift) & ~tos_state_mask) == 0, "no need for tos_state mask"); 390 } 391 392 void verify_just_initialized(bool f2_used); 393 void reinitialize(bool f2_used); 394 }; 395 396 397 // A constant pool cache is a runtime data structure set aside to a constant pool. The cache 398 // holds interpreter runtime information for all field access and invoke bytecodes. The cache 399 // is created and initialized before a class is actively used (i.e., initialized), the indivi- 400 // dual cache entries are filled at resolution (i.e., "link") time (see also: rewriter.*). 401 402 class ConstantPoolCache: public MetaspaceObj { 403 friend class VMStructs; 404 friend class MetadataFactory; 405 private: 406 // If you add a new field that points to any metaspace object, you 407 // must add this field to ConstantPoolCache::metaspace_pointers_do(). 408 int _length; 409 ConstantPool* _constant_pool; // the corresponding constant pool 410 411 // The following fields need to be modified at runtime, so they cannot be 412 // stored in the ConstantPool, which is read-only. 413 // Array of resolved objects from the constant pool and map from resolved 414 // object index to original constant pool index 415 OopHandle _resolved_references; 416 Array<u2>* _reference_map; 417 // The narrowOop pointer to the archived resolved_references. Set at CDS dump 418 // time when caching java heap object is supported. 419 CDS_JAVA_HEAP_ONLY(int _archived_references_index;) 420 421 // Sizing 422 debug_only(friend class ClassVerifier;) 423 424 // Constructor 425 ConstantPoolCache(int length, 426 const intStack& inverse_index_map, 427 const intStack& invokedynamic_inverse_index_map, 428 const intStack& invokedynamic_references_map); 429 430 // Initialization 431 void initialize(const intArray& inverse_index_map, 432 const intArray& invokedynamic_inverse_index_map, 433 const intArray& invokedynamic_references_map); 434 public: 435 static ConstantPoolCache* allocate(ClassLoaderData* loader_data, 436 const intStack& cp_cache_map, 437 const intStack& invokedynamic_cp_cache_map, 438 const intStack& invokedynamic_references_map, TRAPS); 439 length() const440 int length() const { return _length; } 441 void metaspace_pointers_do(MetaspaceClosure* it); type() const442 MetaspaceObj::Type type() const { return ConstantPoolCacheType; } 443 444 oop archived_references() NOT_CDS_JAVA_HEAP_RETURN_(NULL); 445 void set_archived_references(oop o) NOT_CDS_JAVA_HEAP_RETURN; 446 void clear_archived_references() NOT_CDS_JAVA_HEAP_RETURN; 447 448 inline oop resolved_references(); set_resolved_references(OopHandle s)449 void set_resolved_references(OopHandle s) { _resolved_references = s; } reference_map() const450 Array<u2>* reference_map() const { return _reference_map; } set_reference_map(Array<u2> * o)451 void set_reference_map(Array<u2>* o) { _reference_map = o; } 452 453 // Assembly code support resolved_references_offset_in_bytes()454 static int resolved_references_offset_in_bytes() { return offset_of(ConstantPoolCache, _resolved_references); } 455 456 // CDS support 457 void remove_unshareable_info(); 458 void verify_just_initialized(); 459 private: 460 void walk_entries_for_initialization(bool check_only); set_length(int length)461 void set_length(int length) { _length = length; } 462 header_size()463 static int header_size() { return sizeof(ConstantPoolCache) / wordSize; } size(int length)464 static int size(int length) { return align_metadata_size(header_size() + length * in_words(ConstantPoolCacheEntry::size())); } 465 public: size() const466 int size() const { return size(length()); } 467 private: 468 469 // Helpers constant_pool_addr()470 ConstantPool** constant_pool_addr() { return &_constant_pool; } base() const471 ConstantPoolCacheEntry* base() const { return (ConstantPoolCacheEntry*)((address)this + in_bytes(base_offset())); } 472 473 friend class constantPoolCacheKlass; 474 friend class ConstantPoolCacheEntry; 475 476 public: 477 // Accessors set_constant_pool(ConstantPool * pool)478 void set_constant_pool(ConstantPool* pool) { _constant_pool = pool; } constant_pool() const479 ConstantPool* constant_pool() const { return _constant_pool; } 480 // Fetches the entry at the given index. 481 // In either case the index must not be encoded or byte-swapped in any way. entry_at(int i) const482 ConstantPoolCacheEntry* entry_at(int i) const { 483 assert(0 <= i && i < length(), "index out of bounds"); 484 return base() + i; 485 } 486 487 // Code generation base_offset()488 static ByteSize base_offset() { return in_ByteSize(sizeof(ConstantPoolCache)); } entry_offset(int raw_index)489 static ByteSize entry_offset(int raw_index) { 490 int index = raw_index; 491 return (base_offset() + ConstantPoolCacheEntry::size_in_bytes() * index); 492 } 493 494 #if INCLUDE_JVMTI 495 // RedefineClasses() API support: 496 // If any entry of this ConstantPoolCache points to any of 497 // old_methods, replace it with the corresponding new_method. 498 // trace_name_printed is set to true if the current call has 499 // printed the klass name so that other routines in the adjust_* 500 // group don't print the klass name. 501 void adjust_method_entries(bool* trace_name_printed); 502 bool check_no_old_or_obsolete_entries(); 503 void dump_cache(); 504 #endif // INCLUDE_JVMTI 505 506 // RedefineClasses support 507 DEBUG_ONLY(bool on_stack() { return false; }) 508 void deallocate_contents(ClassLoaderData* data); is_klass() const509 bool is_klass() const { return false; } 510 511 // Printing 512 void print_on(outputStream* st) const; 513 void print_value_on(outputStream* st) const; 514 internal_name() const515 const char* internal_name() const { return "{constant pool cache}"; } 516 517 // Verify 518 void verify_on(outputStream* st); 519 }; 520 521 #endif // SHARE_OOPS_CPCACHE_HPP 522