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 #ifndef SHARE_VM_OOPS_CPCACHEOOP_HPP

 #define SHARE_VM_OOPS_CPCACHEOOP_HPP

 #include "interpreter/bytecodes.hpp"

 #include "memory/allocation.hpp"

 #include "oops/arrayOop.hpp"

 #include "utilities/array.hpp"

 // A ConstantPoolCacheEntry describes an individual entry of the constant

 // pool cache. There's 2 principal kinds of entries: field entries for in-

 // stance & static field access, and method entries for invokes. Some of

 // the entry layout is shared and looks as follows:

 //

 // bit number |31                0|

 // bit length |-8--|-8--|---16----|

 // --------------------------------

 // _indices   [ b2 | b1 |  index  ]  index = constant_pool_index (!= 0, normal entries only)

 // _indices   [  index  |  00000  ]  index = main_entry_index (secondary entries only)

 // _f1        [  entry specific   ]  method, klass, or oop (MethodType or CallSite)

 // _f2        [  entry specific   ]  vtable index or vfinal method

 // _flags     [tos|0|00|00|00|f|v|f2|unused|field_index] (for field entries)

 // bit length [ 4 |1|1 |1 | 1|1|1| 1|---5--|----16-----]

 // _flags     [tos|M|vf|fv|ea|f|0|f2|unused|00000|psize] (for method entries)

 // bit length [ 4 |1|1 |1 | 1|1|1| 1|---5--|--8--|--8--]

 // --------------------------------

 //

 // with:

 // index  = original constant pool index

 // b1     = bytecode 1

 // b2     = bytecode 2

 // psize  = parameters size (method entries only)

 // field_index = index into field information in holder instanceKlass

 //          The index max is 0xffff (max number of fields in constant pool)

 //          and is multiplied by (instanceKlass::next_offset) when accessing.

 // t      = TosState (see below)

 // f      = field is marked final (see below)

 // f2     = virtual but final (method entries only: is_vfinal())

 // v      = field is volatile (see below)

 // m      = invokeinterface used for method in class Object (see below)

 // h      = RedefineClasses/Hotswap bit (see below)

 //

 // The flags after TosState have the following interpretation:

 // bit 27: 0 for fields, 1 for methods

 // f  flag true if field is marked final

 // v  flag true if field is volatile (only for fields)

 // f2 flag true if f2 contains an oop (e.g., virtual final method)

 // fv flag true if invokeinterface used for method in class Object

 //

 // The flags 31, 30, 29, 28 together build a 4 bit number 0 to 8 with the

 // following mapping to the TosState states:

 //

 // btos: 0

 // ctos: 1

 // stos: 2

 // itos: 3

 // ltos: 4

 // ftos: 5

 // dtos: 6

 // atos: 7

 // vtos: 8

 //

 // Entry specific: field entries:

 // _indices = get (b1 section) and put (b2 section) bytecodes, original constant pool index

 // _f1      = field holder (as a java.lang.Class, not a klassOop)

 // _f2      = field offset in bytes

 // _flags   = field type information, original FieldInfo index in field holder

 //            (field_index section)

 //

 // Entry specific: method entries:

 // _indices = invoke code for f1 (b1 section), invoke code for f2 (b2 section),

 //            original constant pool index

 // _f1      = methodOop for non-virtual calls, unused by virtual calls.

 //            for interface calls, which are essentially virtual but need a klass,

 //            contains klassOop for the corresponding interface.

 //            for invokedynamic, f1 contains a site-specific CallSite object (as an appendix)

 //            for invokehandle, f1 contains a site-specific MethodType object (as an appendix)

 //            (upcoming metadata changes will move the appendix to a separate array)

 // _f2      = vtable/itable index (or final methodOop) for virtual calls only,

 //            unused by non-virtual.  The is_vfinal flag indicates this is a

 //            method pointer for a final method, not an index.

 // _flags   = method type info (t section),

 //            virtual final bit (vfinal),

 //            parameter size (psize section)

 //

 // Note: invokevirtual & invokespecial bytecodes can share the same constant

 //       pool entry and thus the same constant pool cache entry. All invoke

 //       bytecodes but invokevirtual use only _f1 and the corresponding b1

 //       bytecode, while invokevirtual uses only _f2 and the corresponding

 //       b2 bytecode.  The value of _flags is shared for both types of entries.

 //

 // The fields are volatile so that they are stored in the order written in the

 // source code.  The _indices field with the bytecode must be written last.

 class ConstantPoolCacheEntry VALUE_OBJ_CLASS_SPEC {

   friend class VMStructs;

   friend class constantPoolCacheKlass;

   friend class constantPoolOopDesc;  //resolve_constant_at_impl => set_f1

  private:

   volatile intx     _indices;  // constant pool index & rewrite bytecodes

   volatile oop      _f1;       // entry specific oop field

   volatile intx     _f2;       // entry specific int/oop field

   volatile intx     _flags;    // flags

 #ifdef ASSERT

   bool same_methodOop(oop cur_f1, oop f1);

 #endif

   void set_bytecode_1(Bytecodes::Code code);

   void set_bytecode_2(Bytecodes::Code code);

   void set_f1(oop f1)                            {

     oop existing_f1 = _f1; // read once

     assert(existing_f1 == NULL || existing_f1 == f1, "illegal field change");

     oop_store(&_f1, f1);

   }

   void release_set_f1(oop f1);

   void set_f2(intx f2)                           { assert(_f2 == 0 || _f2 == f2,            "illegal field change"); _f2 = f2; }

   void set_f2_as_vfinal_method(methodOop f2)     { assert(_f2 == 0 || _f2 == (intptr_t) f2, "illegal field change"); assert(is_vfinal(), "flags must be set"); _f2 = (intptr_t) f2; }

   int make_flags(TosState state, int option_bits, int field_index_or_method_params);

   void set_flags(intx flags)                     { _flags = flags; }

   bool init_flags_atomic(intx flags);

   void set_field_flags(TosState field_type, int option_bits, int field_index) {

     assert((field_index & field_index_mask) == field_index, "field_index in range");

     set_flags(make_flags(field_type, option_bits | (1 << is_field_entry_shift), field_index));

   }

   void set_method_flags(TosState return_type, int option_bits, int method_params) {

     assert((method_params & parameter_size_mask) == method_params, "method_params in range");

     set_flags(make_flags(return_type, option_bits, method_params));

   }

   bool init_method_flags_atomic(TosState return_type, int option_bits, int method_params) {

     assert((method_params & parameter_size_mask) == method_params, "method_params in range");

     return init_flags_atomic(make_flags(return_type, option_bits, method_params));

   }

  public:

   // specific bit definitions for the flags field:

   // (Note: the interpreter must use these definitions to access the CP cache.)

   enum {

     // high order bits are the TosState corresponding to field type or method return type

     tos_state_bits             = 4,

     tos_state_mask             = right_n_bits(tos_state_bits),

     tos_state_shift            = BitsPerInt - tos_state_bits,  // see verify_tos_state_shift below

     // misc. option bits; can be any bit position in [16..27]

     is_vfinal_shift            = 21,

     is_volatile_shift          = 22,

     is_final_shift             = 23,

     has_appendix_shift         = 24,

     is_forced_virtual_shift    = 25,

     is_field_entry_shift       = 26,

     // low order bits give field index (for FieldInfo) or method parameter size:

     field_index_bits           = 16,

     field_index_mask           = right_n_bits(field_index_bits),

     parameter_size_bits        = 8,  // subset of field_index_mask, range is 0..255

     parameter_size_mask        = right_n_bits(parameter_size_bits),

     option_bits_mask           = ~(((-1) << tos_state_shift) | (field_index_mask | parameter_size_mask))

   };

   // specific bit definitions for the indices field:

   enum {

     main_cp_index_bits         = 2*BitsPerByte,

     main_cp_index_mask         = right_n_bits(main_cp_index_bits),

     bytecode_1_shift           = main_cp_index_bits,

     bytecode_1_mask            = right_n_bits(BitsPerByte), // == (u1)0xFF

     bytecode_2_shift           = main_cp_index_bits + BitsPerByte,

     bytecode_2_mask            = right_n_bits(BitsPerByte), // == (u1)0xFF

     // the secondary cp index overlaps with bytecodes 1 and 2:

     secondary_cp_index_shift   = bytecode_1_shift,

     secondary_cp_index_bits    = BitsPerInt - main_cp_index_bits

   };

   // Initialization

   void initialize_entry(int original_index);     // initialize primary entry

   void initialize_secondary_entry(int main_index); // initialize secondary entry

   void set_field(                                // sets entry to resolved field state

     Bytecodes::Code get_code,                    // the bytecode used for reading the field

     Bytecodes::Code put_code,                    // the bytecode used for writing the field

     KlassHandle     field_holder,                // the object/klass holding the field

     int             orig_field_index,            // the original field index in the field holder

     int             field_offset,                // the field offset in words in the field holder

     TosState        field_type,                  // the (machine) field type

     bool            is_final,                     // the field is final

     bool            is_volatile                  // the field is volatile

   );

   void set_method(                               // sets entry to resolved method entry

     Bytecodes::Code invoke_code,                 // the bytecode used for invoking the method

     methodHandle    method,                      // the method/prototype if any (NULL, otherwise)

     int             vtable_index                 // the vtable index if any, else negative

   );

   void set_interface_call(

     methodHandle method,                         // Resolved method

     int index                                    // Method index into interface

   );

   void set_method_handle(

     methodHandle method,                         // adapter for invokeExact, etc.

     Handle appendix                              // stored in f1; could be a java.lang.invoke.MethodType

   );

   void set_dynamic_call(

     methodHandle method,                         // adapter for this call site

     Handle appendix                              // stored in f1; could be a java.lang.invoke.CallSite

   );

   // Common code for invokedynamic and MH invocations.

   // The "appendix" is an optional call-site-specific parameter which is

   // pushed by the JVM at the end of the argument list.  This argument may

   // be a MethodType for the MH.invokes and a CallSite for an invokedynamic

   // instruction.  However, its exact type and use depends on the Java upcall,

   // which simply returns a compiled LambdaForm along with any reference

   // that LambdaForm needs to complete the call.  If the upcall returns a

   // null appendix, the argument is not passed at all.

   //

   // The appendix is *not* represented in the signature of the symbolic

   // reference for the call site, but (if present) it *is* represented in

   // the methodOop bound to the site.  This means that static and dynamic

   // resolution logic needs to make slightly different assessments about the

   // number and types of arguments.

   void set_method_handle_common(

     Bytecodes::Code invoke_code,                 // _invokehandle or _invokedynamic

     methodHandle adapter,                        // invoker method (f2)

     Handle appendix                              // appendix such as CallSite, MethodType, etc. (f1)

   );

   methodOop method_if_resolved(constantPoolHandle cpool);

   void set_parameter_size(int value);

   // Which bytecode number (1 or 2) in the index field is valid for this bytecode?

   // Returns -1 if neither is valid.

   static int bytecode_number(Bytecodes::Code code) {

     switch (code) {

       case Bytecodes::_getstatic       :    // fall through

       case Bytecodes::_getfield        :    // fall through

       case Bytecodes::_invokespecial   :    // fall through

       case Bytecodes::_invokestatic    :    // fall through

       case Bytecodes::_invokeinterface : return 1;

       case Bytecodes::_putstatic       :    // fall through

       case Bytecodes::_putfield        :    // fall through

       case Bytecodes::_invokehandle    :    // fall through

       case Bytecodes::_invokedynamic   :    // fall through

       case Bytecodes::_invokevirtual   : return 2;

       default                          : break;

     }

     return -1;

   }

   // Has this bytecode been resolved? Only valid for invokes and get/put field/static.

   bool is_resolved(Bytecodes::Code code) const {

     switch (bytecode_number(code)) {

       case 1:  return (bytecode_1() == code);

       case 2:  return (bytecode_2() == code);

     }

     return false;      // default: not resolved

   }

   // Accessors

   bool is_secondary_entry() const                { return (_indices & main_cp_index_mask) == 0; }

   int main_entry_index() const                   { assert(is_secondary_entry(), "must be secondary entry");

                                                    return ((uintx)_indices >> secondary_cp_index_shift); }

   int primary_entry_indices() const              { assert(!is_secondary_entry(), "must be main entry");

                                                    return _indices; }

   int constant_pool_index() const                { return (primary_entry_indices() & main_cp_index_mask); }

   Bytecodes::Code bytecode_1() const             { return Bytecodes::cast((primary_entry_indices() >> bytecode_1_shift)

                                                                           & bytecode_1_mask); }

   Bytecodes::Code bytecode_2() const             { return Bytecodes::cast((primary_entry_indices() >> bytecode_2_shift)

                                                                           & bytecode_2_mask); }

   methodOop f1_as_method() const                 { oop f1 = _f1; assert(f1 == NULL || f1->is_method(), ""); return methodOop(f1); }

   klassOop  f1_as_klass() const                  { oop f1 = _f1; assert(f1 == NULL || f1->is_klass(), ""); return klassOop(f1); }

   oop       f1_as_klass_mirror() const           { oop f1 = f1_as_instance(); return f1; }  // i.e., return a java_mirror

   oop       f1_as_instance() const               { oop f1 = _f1; assert(f1 == NULL || f1->is_instance() || f1->is_array(), ""); return f1; }

   oop       f1_appendix() const                  { assert(has_appendix(), ""); return f1_as_instance(); }

   bool      is_f1_null() const                   { oop f1 = _f1; return f1 == NULL; }  // classifies a CPC entry as unbound

   int       f2_as_index() const                  { assert(!is_vfinal(), ""); return (int) _f2; }

   methodOop f2_as_vfinal_method() const          { assert(is_vfinal(), ""); return methodOop(_f2); }

   int  field_index() const                       { assert(is_field_entry(),  ""); return (_flags & field_index_mask); }

   int  parameter_size() const                    { assert(is_method_entry(), ""); return (_flags & parameter_size_mask); }

   bool is_volatile() const                       { return (_flags & (1 << is_volatile_shift))       != 0; }

   bool is_final() const                          { return (_flags & (1 << is_final_shift))          != 0; }

   bool has_appendix() const                      { return (_flags & (1 << has_appendix_shift))     != 0; }

   bool is_forced_virtual() const                 { return (_flags & (1 << is_forced_virtual_shift)) != 0; }

   bool is_vfinal() const                         { return (_flags & (1 << is_vfinal_shift))         != 0; }

   bool is_method_entry() const                   { return (_flags & (1 << is_field_entry_shift))    == 0; }

   bool is_field_entry() const                    { return (_flags & (1 << is_field_entry_shift))    != 0; }

   bool is_byte() const                           { return flag_state() == btos; }

   bool is_char() const                           { return flag_state() == ctos; }

   bool is_short() const                          { return flag_state() == stos; }

   bool is_int() const                            { return flag_state() == itos; }

   bool is_long() const                           { return flag_state() == ltos; }

   bool is_float() const                          { return flag_state() == ftos; }

   bool is_double() const                         { return flag_state() == dtos; }

   bool is_object() const                         { return flag_state() == atos; }

   TosState flag_state() const                    { assert((uint)number_of_states <= (uint)tos_state_mask+1, "");

                                                    return (TosState)((_flags >> tos_state_shift) & tos_state_mask); }

   // Code generation support

   static WordSize size()                         { return in_WordSize(sizeof(ConstantPoolCacheEntry) / HeapWordSize); }

   static ByteSize size_in_bytes()                { return in_ByteSize(sizeof(ConstantPoolCacheEntry)); }

   static ByteSize indices_offset()               { return byte_offset_of(ConstantPoolCacheEntry, _indices); }

   static ByteSize f1_offset()                    { return byte_offset_of(ConstantPoolCacheEntry, _f1); }

   static ByteSize f2_offset()                    { return byte_offset_of(ConstantPoolCacheEntry, _f2); }

   static ByteSize flags_offset()                 { return byte_offset_of(ConstantPoolCacheEntry, _flags); }

   // GC Support

   void oops_do(void f(oop*));

   void oop_iterate(OopClosure* blk);

   void oop_iterate_m(OopClosure* blk, MemRegion mr);

   void follow_contents();

   void adjust_pointers();

 #ifndef SERIALGC

   // Parallel Old

   void follow_contents(ParCompactionManager* cm);

 #endif // SERIALGC

   void update_pointers();

   // RedefineClasses() API support:

   // If this constantPoolCacheEntry refers to old_method then update it

   // to refer to new_method.

   // trace_name_printed is set to true if the current call has

   // printed the klass name so that other routines in the adjust_*

   // group don't print the klass name.

   bool adjust_method_entry(methodOop old_method, methodOop new_method,

          bool * trace_name_printed);

   bool is_interesting_method_entry(klassOop k);

   // Debugging & Printing

   void print (outputStream* st, int index) const;

   void verify(outputStream* st) const;

   static void verify_tos_state_shift() {

     // When shifting flags as a 32-bit int, make sure we don't need an extra mask for tos_state:

     assert((((u4)-1 >> tos_state_shift) & ~tos_state_mask) == 0, "no need for tos_state mask");

   }

 };

 // A constant pool cache is a runtime data structure set aside to a constant pool. The cache

 // holds interpreter runtime information for all field access and invoke bytecodes. The cache

 // is created and initialized before a class is actively used (i.e., initialized), the indivi-

 // dual cache entries are filled at resolution (i.e., "link") time (see also: rewriter.*).

 class constantPoolCacheOopDesc: public oopDesc {

   friend class VMStructs;

  private:

   int             _length;

   constantPoolOop _constant_pool;                // the corresponding constant pool

   // Sizing

   debug_only(friend class ClassVerifier;)

  public:

   int length() const                             { return _length; }

  private:

   void set_length(int length)                    { _length = length; }

   static int header_size()                       { return sizeof(constantPoolCacheOopDesc) / HeapWordSize; }

   static int object_size(int length)             { return align_object_size(header_size() + length * in_words(ConstantPoolCacheEntry::size())); }

   int object_size()                              { return object_size(length()); }

   // Helpers

   constantPoolOop*        constant_pool_addr()   { return &_constant_pool; }

   ConstantPoolCacheEntry* base() const           { return (ConstantPoolCacheEntry*)((address)this + in_bytes(base_offset())); }

   friend class constantPoolCacheKlass;

   friend class ConstantPoolCacheEntry;

  public:

   // Initialization

   void initialize(intArray& inverse_index_map);

   // Secondary indexes.

   // They must look completely different from normal indexes.

   // The main reason is that byte swapping is sometimes done on normal indexes.

   // Also, some of the CP accessors do different things for secondary indexes.

   // Finally, it is helpful for debugging to tell the two apart.

   static bool is_secondary_index(int i) { return (i < 0); }

   static int  decode_secondary_index(int i) { assert(is_secondary_index(i),  ""); return ~i; }

   static int  encode_secondary_index(int i) { assert(!is_secondary_index(i), ""); return ~i; }

   // Accessors

   void set_constant_pool(constantPoolOop pool)   { oop_store_without_check((oop*)&_constant_pool, (oop)pool); }

   constantPoolOop constant_pool() const          { return _constant_pool; }

   // Fetches the entry at the given index.

   // The entry may be either primary or secondary.

   // In either case the index must not be encoded or byte-swapped in any way.

   ConstantPoolCacheEntry* entry_at(int i) const {

     assert(0 <= i && i < length(), "index out of bounds");

     return base() + i;

   }

   // Fetches the secondary entry referred to by index.

   // The index may be a secondary index, and must not be byte-swapped.

   ConstantPoolCacheEntry* secondary_entry_at(int i) const {

     int raw_index = i;

     if (is_secondary_index(i)) {  // correct these on the fly

       raw_index = decode_secondary_index(i);

     }

     assert(entry_at(raw_index)->is_secondary_entry(), "not a secondary entry");

     return entry_at(raw_index);

   }

   // Given a primary or secondary index, fetch the corresponding primary entry.

   // Indirect through the secondary entry, if the index is encoded as a secondary index.

   // The index must not be byte-swapped.

   ConstantPoolCacheEntry* main_entry_at(int i) const {

     int primary_index = i;

     if (is_secondary_index(i)) {

       // run through an extra level of indirection:

       int raw_index = decode_secondary_index(i);

       primary_index = entry_at(raw_index)->main_entry_index();

     }

     assert(!entry_at(primary_index)->is_secondary_entry(), "only one level of indirection");

     return entry_at(primary_index);

   }

   // Code generation

   static ByteSize base_offset()                  { return in_ByteSize(sizeof(constantPoolCacheOopDesc)); }

   static ByteSize entry_offset(int raw_index) {

     int index = raw_index;

     if (is_secondary_index(raw_index))

       index = decode_secondary_index(raw_index);

     return (base_offset() + ConstantPoolCacheEntry::size_in_bytes() * index);

   }

   // RedefineClasses() API support:

   // If any entry of this constantPoolCache points to any of

   // old_methods, replace it with the corresponding new_method.

   // trace_name_printed is set to true if the current call has

   // printed the klass name so that other routines in the adjust_*

   // group don't print the klass name.

   void adjust_method_entries(methodOop* old_methods, methodOop* new_methods,

                              int methods_length, bool * trace_name_printed);

 };

 #endif // SHARE_VM_OOPS_CPCACHEOOP_HPP