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