1 /*
   2  * Copyright (c) 1998, 2012, 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
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  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 "utilities/array.hpp"
  31 
  32 class PSPromotionManager;
  33 
  34 // A ConstantPoolCacheEntry describes an individual entry of the constant
  35 // pool cache. There's 2 principal kinds of entries: field entries for in-
  36 // stance & static field access, and method entries for invokes. Some of
  37 // the entry layout is shared and looks as follows:
  38 //
  39 // bit number |31                0|
  40 // bit length |-8--|-8--|---16----|
  41 // --------------------------------
  42 // _indices   [ b2 | b1 |  index  ]  index = constant_pool_index
  43 // _f1        [  entry specific   ]  metadata ptr (method or klass)
  44 // _f2        [  entry specific   ]  vtable or res_ref index, or vfinal method ptr
  45 // _flags     [tos|0|F=1|0|0|0|f|v|0 |0000|field_index] (for field entries)
  46 // bit length [ 4 |1| 1 |1|1|1|1|1|1 |-4--|----16-----]
  47 // _flags     [tos|0|F=0|M|A|I|f|0|vf|0000|00000|psize] (for method entries)
  48 // bit length [ 4 |1| 1 |1|1|1|1|1|1 |-4--|--8--|--8--]
  49 
  50 // --------------------------------
  51 //
  52 // with:
  53 // index  = original constant pool index
  54 // b1     = bytecode 1
  55 // b2     = bytecode 2
  56 // psize  = parameters size (method entries only)
  57 // field_index = index into field information in holder InstanceKlass
  58 //          The index max is 0xffff (max number of fields in constant pool)
  59 //          and is multiplied by (InstanceKlass::next_offset) when accessing.
  60 // tos    = TosState
  61 // F      = the entry is for a field (or F=0 for a method)
  62 // A      = call site has an appendix argument (loaded from resolved references)
  63 // I      = interface call is forced virtual (must use a vtable index or vfinal)
  64 // f      = field or method is final
  65 // v      = field is volatile
  66 // vf     = virtual but final (method entries only: is_vfinal())
  67 //
  68 // The flags after TosState have the following interpretation:
  69 // bit 27: 0 for fields, 1 for methods
  70 // f  flag true if field is marked final
  71 // v  flag true if field is volatile (only for fields)
  72 // f2 flag true if f2 contains an oop (e.g., virtual final method)
  73 // fv flag true if invokeinterface used for method in class Object
  74 //
  75 // The flags 31, 30, 29, 28 together build a 4 bit number 0 to 8 with the
  76 // following mapping to the TosState states:
  77 //
  78 // btos: 0
  79 // ctos: 1
  80 // stos: 2
  81 // itos: 3
  82 // ltos: 4
  83 // ftos: 5
  84 // dtos: 6
  85 // atos: 7
  86 // vtos: 8
  87 //
  88 // Entry specific: field entries:
  89 // _indices = get (b1 section) and put (b2 section) bytecodes, original constant pool index
  90 // _f1      = field holder (as a java.lang.Class, not a Klass*)
  91 // _f2      = field offset in bytes
  92 // _flags   = field type information, original FieldInfo index in field holder
  93 //            (field_index section)
  94 //
  95 // Entry specific: method entries:
  96 // _indices = invoke code for f1 (b1 section), invoke code for f2 (b2 section),
  97 //            original constant pool index
  98 // _f1      = Method* for non-virtual calls, unused by virtual calls.
  99 //            for interface calls, which are essentially virtual but need a klass,
 100 //            contains Klass* for the corresponding interface.
 101 //            for invokedynamic, f1 contains a site-specific CallSite object (as an appendix)
 102 //            for invokehandle, f1 contains a site-specific MethodType object (as an appendix)
 103 //            (upcoming metadata changes will move the appendix to a separate array)
 104 // _f2      = vtable/itable index (or final Method*) for virtual calls only,
 105 //            unused by non-virtual.  The is_vfinal flag indicates this is a
 106 //            method pointer for a final method, not an index.
 107 // _flags   = method type info (t section),
 108 //            virtual final bit (vfinal),
 109 //            parameter size (psize section)
 110 //
 111 // Note: invokevirtual & invokespecial bytecodes can share the same constant
 112 //       pool entry and thus the same constant pool cache entry. All invoke
 113 //       bytecodes but invokevirtual use only _f1 and the corresponding b1
 114 //       bytecode, while invokevirtual uses only _f2 and the corresponding
 115 //       b2 bytecode.  The value of _flags is shared for both types of entries.
 116 //
 117 // The fields are volatile so that they are stored in the order written in the
 118 // source code.  The _indices field with the bytecode must be written last.
 119 
 120 class CallInfo;
 121 
 122 class ConstantPoolCacheEntry VALUE_OBJ_CLASS_SPEC {
 123   friend class VMStructs;
 124   friend class constantPoolCacheKlass;
 125   friend class ConstantPool;
 126   friend class InterpreterRuntime;
 127 
 128  private:
 129   volatile intx     _indices;  // constant pool index & rewrite bytecodes
 130   volatile Metadata*   _f1;       // entry specific metadata field
 131   volatile intx        _f2;       // entry specific int/metadata field
 132   volatile intx     _flags;    // flags
 133 
 134 
 135   void set_bytecode_1(Bytecodes::Code code);
 136   void set_bytecode_2(Bytecodes::Code code);
 137   void set_f1(Metadata* f1)                            {
 138     Metadata* existing_f1 = (Metadata*)_f1; // read once
 139     assert(existing_f1 == NULL || existing_f1 == f1, "illegal field change");
 140     _f1 = f1;
 141   }
 142   void release_set_f1(Metadata* f1);
 143   void set_f2(intx f2)                           { assert(_f2 == 0 || _f2 == f2,            "illegal field change"); _f2 = f2; }
 144   void set_f2_as_vfinal_method(Method* f2)     { assert(_f2 == 0 || _f2 == (intptr_t) f2, "illegal field change"); assert(is_vfinal(), "flags must be set"); _f2 = (intptr_t) f2; }
 145   int make_flags(TosState state, int option_bits, int field_index_or_method_params);
 146   void set_flags(intx flags)                     { _flags = flags; }
 147   bool init_flags_atomic(intx flags);
 148   void set_field_flags(TosState field_type, int option_bits, int field_index) {
 149     assert((field_index & field_index_mask) == field_index, "field_index in range");
 150     set_flags(make_flags(field_type, option_bits | (1 << is_field_entry_shift), field_index));
 151   }
 152   void set_method_flags(TosState return_type, int option_bits, int method_params) {
 153     assert((method_params & parameter_size_mask) == method_params, "method_params in range");
 154     set_flags(make_flags(return_type, option_bits, method_params));
 155   }
 156   bool init_method_flags_atomic(TosState return_type, int option_bits, int method_params) {
 157     assert((method_params & parameter_size_mask) == method_params, "method_params in range");
 158     return init_flags_atomic(make_flags(return_type, option_bits, method_params));
 159   }
 160 
 161  public:
 162   // specific bit definitions for the flags field:
 163   // (Note: the interpreter must use these definitions to access the CP cache.)
 164   enum {
 165     // high order bits are the TosState corresponding to field type or method return type
 166     tos_state_bits             = 4,
 167     tos_state_mask             = right_n_bits(tos_state_bits),
 168     tos_state_shift            = BitsPerInt - tos_state_bits,  // see verify_tos_state_shift below
 169     // misc. option bits; can be any bit position in [16..27]
 170     is_field_entry_shift       = 26,  // (F) is it a field or a method?
 171     has_method_type_shift      = 25,  // (M) does the call site have a MethodType?
 172     has_appendix_shift         = 24,  // (A) does the call site have an appendix argument?
 173     is_forced_virtual_shift    = 23,  // (I) is the interface reference forced to virtual mode?
 174     is_final_shift             = 22,  // (f) is the field or method final?
 175     is_volatile_shift          = 21,  // (v) is the field volatile?
 176     is_vfinal_shift            = 20,  // (vf) did the call resolve to a final method?
 177     // low order bits give field index (for FieldInfo) or method parameter size:
 178     field_index_bits           = 16,
 179     field_index_mask           = right_n_bits(field_index_bits),
 180     parameter_size_bits        = 8,  // subset of field_index_mask, range is 0..255
 181     parameter_size_mask        = right_n_bits(parameter_size_bits),
 182     option_bits_mask           = ~(((-1) << tos_state_shift) | (field_index_mask | parameter_size_mask))
 183   };
 184 
 185   // specific bit definitions for the indices field:
 186   enum {
 187     cp_index_bits              = 2*BitsPerByte,
 188     cp_index_mask              = right_n_bits(cp_index_bits),
 189     bytecode_1_shift           = cp_index_bits,
 190     bytecode_1_mask            = right_n_bits(BitsPerByte), // == (u1)0xFF
 191     bytecode_2_shift           = cp_index_bits + BitsPerByte,
 192     bytecode_2_mask            = right_n_bits(BitsPerByte)  // == (u1)0xFF
 193   };
 194 
 195 
 196   // Initialization
 197   void initialize_entry(int original_index);     // initialize primary entry
 198   void initialize_resolved_reference_index(int ref_index) {
 199     assert(_f2 == 0, "set once");  // note: ref_index might be zero also
 200     _f2 = ref_index;
 201   }
 202 
 203   void set_field(                                // sets entry to resolved field state
 204     Bytecodes::Code get_code,                    // the bytecode used for reading the field
 205     Bytecodes::Code put_code,                    // the bytecode used for writing the field
 206     KlassHandle     field_holder,                // the object/klass holding the field
 207     int             orig_field_index,            // the original field index in the field holder
 208     int             field_offset,                // the field offset in words in the field holder
 209     TosState        field_type,                  // the (machine) field type
 210     bool            is_final,                     // the field is final
 211     bool            is_volatile,                 // the field is volatile
 212     Klass*          root_klass                   // needed by the GC to dirty the klass
 213   );
 214 
 215   void set_method(                               // sets entry to resolved method entry
 216     Bytecodes::Code invoke_code,                 // the bytecode used for invoking the method
 217     methodHandle    method,                      // the method/prototype if any (NULL, otherwise)
 218     int             vtable_index                 // the vtable index if any, else negative
 219   );
 220 
 221   void set_interface_call(
 222     methodHandle method,                         // Resolved method
 223     int index                                    // Method index into interface
 224   );
 225 
 226   void set_method_handle(
 227     constantPoolHandle cpool,                    // holding constant pool (required for locking)
 228     const CallInfo &call_info                    // Call link information
 229   );
 230 
 231   void set_dynamic_call(
 232     constantPoolHandle cpool,                    // holding constant pool (required for locking)
 233     const CallInfo &call_info                    // Call link information
 234   );
 235 
 236   // Common code for invokedynamic and MH invocations.
 237 
 238   // The "appendix" is an optional call-site-specific parameter which is
 239   // pushed by the JVM at the end of the argument list.  This argument may
 240   // be a MethodType for the MH.invokes and a CallSite for an invokedynamic
 241   // instruction.  However, its exact type and use depends on the Java upcall,
 242   // which simply returns a compiled LambdaForm along with any reference
 243   // that LambdaForm needs to complete the call.  If the upcall returns a
 244   // null appendix, the argument is not passed at all.
 245   //
 246   // The appendix is *not* represented in the signature of the symbolic
 247   // reference for the call site, but (if present) it *is* represented in
 248   // the Method* bound to the site.  This means that static and dynamic
 249   // resolution logic needs to make slightly different assessments about the
 250   // number and types of arguments.
 251   void set_method_handle_common(
 252     constantPoolHandle cpool,                    // holding constant pool (required for locking)
 253     Bytecodes::Code invoke_code,                 // _invokehandle or _invokedynamic
 254     const CallInfo &call_info                    // Call link information
 255   );
 256 
 257   // invokedynamic and invokehandle call sites have two entries in the
 258   // resolved references array:
 259   //   appendix   (at index+0)
 260   //   MethodType (at index+1)
 261   enum {
 262     _indy_resolved_references_appendix_offset    = 0,
 263     _indy_resolved_references_method_type_offset = 1,
 264     _indy_resolved_references_entries
 265   };
 266 
 267   Method*      method_if_resolved(constantPoolHandle cpool);
 268   oop        appendix_if_resolved(constantPoolHandle cpool);
 269   oop     method_type_if_resolved(constantPoolHandle cpool);
 270 
 271   void set_parameter_size(int value);
 272 
 273   // Which bytecode number (1 or 2) in the index field is valid for this bytecode?
 274   // Returns -1 if neither is valid.
 275   static int bytecode_number(Bytecodes::Code code) {
 276     switch (code) {
 277       case Bytecodes::_getstatic       :    // fall through
 278       case Bytecodes::_getfield        :    // fall through
 279       case Bytecodes::_invokespecial   :    // fall through
 280       case Bytecodes::_invokestatic    :    // fall through
 281       case Bytecodes::_invokehandle    :    // fall through
 282       case Bytecodes::_invokedynamic   :    // fall through
 283       case Bytecodes::_invokeinterface : return 1;
 284       case Bytecodes::_putstatic       :    // fall through
 285       case Bytecodes::_putfield        :    // fall through
 286       case Bytecodes::_invokevirtual   : return 2;
 287       default                          : break;
 288     }
 289     return -1;
 290   }
 291 
 292   // Has this bytecode been resolved? Only valid for invokes and get/put field/static.
 293   bool is_resolved(Bytecodes::Code code) const {
 294     switch (bytecode_number(code)) {
 295       case 1:  return (bytecode_1() == code);
 296       case 2:  return (bytecode_2() == code);
 297     }
 298     return false;      // default: not resolved
 299   }
 300 
 301   // Accessors
 302   int indices() const                            { return _indices; }
 303   int constant_pool_index() const                { return (indices() & cp_index_mask); }
 304   Bytecodes::Code bytecode_1() const             { return Bytecodes::cast((indices() >> bytecode_1_shift) & bytecode_1_mask); }
 305   Bytecodes::Code bytecode_2() const             { return Bytecodes::cast((indices() >> bytecode_2_shift) & bytecode_2_mask); }
 306   Method* f1_as_method() const                   { Metadata* f1 = (Metadata*)_f1; assert(f1 == NULL || f1->is_method(), ""); return (Method*)f1; }
 307   Klass*    f1_as_klass() const                  { Metadata* f1 = (Metadata*)_f1; assert(f1 == NULL || f1->is_klass(), ""); return (Klass*)f1; }
 308   bool      is_f1_null() const                   { Metadata* f1 = (Metadata*)_f1; return f1 == NULL; }  // classifies a CPC entry as unbound
 309   int       f2_as_index() const                  { assert(!is_vfinal(), ""); return (int) _f2; }
 310   Method* f2_as_vfinal_method() const            { assert(is_vfinal(), ""); return (Method*)_f2; }
 311   int  field_index() const                       { assert(is_field_entry(),  ""); return (_flags & field_index_mask); }
 312   int  parameter_size() const                    { assert(is_method_entry(), ""); return (_flags & parameter_size_mask); }
 313   bool is_volatile() const                       { return (_flags & (1 << is_volatile_shift))       != 0; }
 314   bool is_final() const                          { return (_flags & (1 << is_final_shift))          != 0; }
 315   bool is_forced_virtual() const                 { return (_flags & (1 << is_forced_virtual_shift)) != 0; }
 316   bool is_vfinal() const                         { return (_flags & (1 << is_vfinal_shift))         != 0; }
 317   bool has_appendix() const                      { return (_flags & (1 << has_appendix_shift))      != 0; }
 318   bool has_method_type() const                   { return (_flags & (1 << has_method_type_shift))   != 0; }
 319   bool is_method_entry() const                   { return (_flags & (1 << is_field_entry_shift))    == 0; }
 320   bool is_field_entry() const                    { return (_flags & (1 << is_field_entry_shift))    != 0; }
 321   bool is_byte() const                           { return flag_state() == btos; }
 322   bool is_char() const                           { return flag_state() == ctos; }
 323   bool is_short() const                          { return flag_state() == stos; }
 324   bool is_int() const                            { return flag_state() == itos; }
 325   bool is_long() const                           { return flag_state() == ltos; }
 326   bool is_float() const                          { return flag_state() == ftos; }
 327   bool is_double() const                         { return flag_state() == dtos; }
 328   bool is_object() const                         { return flag_state() == atos; }
 329   TosState flag_state() const                    { assert((uint)number_of_states <= (uint)tos_state_mask+1, "");
 330                                                    return (TosState)((_flags >> tos_state_shift) & tos_state_mask); }
 331 
 332   // Code generation support
 333   static WordSize size()                         { return in_WordSize(sizeof(ConstantPoolCacheEntry) / HeapWordSize); }
 334   static ByteSize size_in_bytes()                { return in_ByteSize(sizeof(ConstantPoolCacheEntry)); }
 335   static ByteSize indices_offset()               { return byte_offset_of(ConstantPoolCacheEntry, _indices); }
 336   static ByteSize f1_offset()                    { return byte_offset_of(ConstantPoolCacheEntry, _f1); }
 337   static ByteSize f2_offset()                    { return byte_offset_of(ConstantPoolCacheEntry, _f2); }
 338   static ByteSize flags_offset()                 { return byte_offset_of(ConstantPoolCacheEntry, _flags); }
 339 

 340   // RedefineClasses() API support:
 341   // If this constantPoolCacheEntry refers to old_method then update it
 342   // to refer to new_method.
 343   // trace_name_printed is set to true if the current call has
 344   // printed the klass name so that other routines in the adjust_*
 345   // group don't print the klass name.
 346   bool adjust_method_entry(Method* old_method, Method* new_method,
 347          bool * trace_name_printed);
 348   NOT_PRODUCT(bool check_no_old_entries();)
 349   bool is_interesting_method_entry(Klass* k);

 350 
 351   // Debugging & Printing
 352   void print (outputStream* st, int index) const;
 353   void verify(outputStream* st) const;
 354 
 355   static void verify_tos_state_shift() {
 356     // When shifting flags as a 32-bit int, make sure we don't need an extra mask for tos_state:
 357     assert((((u4)-1 >> tos_state_shift) & ~tos_state_mask) == 0, "no need for tos_state mask");
 358   }
 359 };
 360 
 361 
 362 // A constant pool cache is a runtime data structure set aside to a constant pool. The cache
 363 // holds interpreter runtime information for all field access and invoke bytecodes. The cache
 364 // is created and initialized before a class is actively used (i.e., initialized), the indivi-
 365 // dual cache entries are filled at resolution (i.e., "link") time (see also: rewriter.*).
 366 
 367 class ConstantPoolCache: public MetaspaceObj {
 368   friend class VMStructs;
 369   friend class MetadataFactory;
 370  private:
 371   int             _length;
 372   ConstantPool* _constant_pool;                // the corresponding constant pool
 373 
 374   // Sizing
 375   debug_only(friend class ClassVerifier;)
 376 
 377   // Constructor
 378   ConstantPoolCache(int length) : _length(length), _constant_pool(NULL) {
 379     for (int i = 0; i < length; i++) {
 380       assert(entry_at(i)->is_f1_null(), "Failed to clear?");
 381     }
 382   }
 383 
 384  public:
 385   static ConstantPoolCache* allocate(ClassLoaderData* loader_data, int length, TRAPS);
 386   bool is_constantPoolCache() const { return true; }
 387 
 388   int length() const                             { return _length; }
 389  private:
 390   void set_length(int length)                    { _length = length; }
 391 
 392   static int header_size()                       { return sizeof(ConstantPoolCache) / HeapWordSize; }
 393   static int size(int length)                    { return align_object_size(header_size() + length * in_words(ConstantPoolCacheEntry::size())); }
 394  public:
 395   int size() const                               { return size(length()); }
 396  private:
 397 
 398   // Helpers
 399   ConstantPool**        constant_pool_addr()   { return &_constant_pool; }
 400   ConstantPoolCacheEntry* base() const           { return (ConstantPoolCacheEntry*)((address)this + in_bytes(base_offset())); }
 401 
 402   friend class constantPoolCacheKlass;
 403   friend class ConstantPoolCacheEntry;
 404 
 405  public:
 406   // Initialization
 407   void initialize(intArray& inverse_index_map, intArray& invokedynamic_references_map);
 408 
 409   // Accessors
 410   void set_constant_pool(ConstantPool* pool)   { _constant_pool = pool; }
 411   ConstantPool* constant_pool() const          { return _constant_pool; }
 412   // Fetches the entry at the given index.
 413   // In either case the index must not be encoded or byte-swapped in any way.
 414   ConstantPoolCacheEntry* entry_at(int i) const {
 415     assert(0 <= i && i < length(), "index out of bounds");
 416     return base() + i;
 417   }
 418 
 419   // Code generation
 420   static ByteSize base_offset()                  { return in_ByteSize(sizeof(ConstantPoolCache)); }
 421   static ByteSize entry_offset(int raw_index) {
 422     int index = raw_index;
 423     return (base_offset() + ConstantPoolCacheEntry::size_in_bytes() * index);
 424   }
 425 

 426   // RedefineClasses() API support:
 427   // If any entry of this constantPoolCache points to any of
 428   // old_methods, replace it with the corresponding new_method.
 429   // trace_name_printed is set to true if the current call has
 430   // printed the klass name so that other routines in the adjust_*
 431   // group don't print the klass name.
 432   void adjust_method_entries(Method** old_methods, Method** new_methods,
 433                              int methods_length, bool * trace_name_printed);
 434   NOT_PRODUCT(bool check_no_old_entries();)


 435 
 436   // Deallocate - no fields to deallocate
 437   DEBUG_ONLY(bool on_stack() { return false; })
 438   void deallocate_contents(ClassLoaderData* data) {}
 439   bool is_klass() const { return false; }
 440 
 441   // Printing
 442   void print_on(outputStream* st) const;
 443   void print_value_on(outputStream* st) const;
 444 
 445   const char* internal_name() const { return "{constant pool cache}"; }
 446 
 447   // Verify
 448   void verify_on(outputStream* st);
 449 };
 450 
 451 #endif // SHARE_VM_OOPS_CPCACHEOOP_HPP
--- EOF ---