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 /*

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  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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  * published by the Free Software Foundation.

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  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

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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 "runtime/orderAccess.hpp"

 #include "utilities/array.hpp"

 class PSPromotionManager;

 // The ConstantPoolCache is not a cache! It is the resolution table that the

 // interpreter uses to avoid going into the runtime and a way to access resolved

 // values.

 // 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

 // _f1        [  entry specific   ]  metadata ptr (method or klass)

 // _f2        [  entry specific   ]  vtable or res_ref index, or vfinal method ptr

 // _flags     [tos|0|F=1|0|0|0|f|v|0 |0000|field_index] (for field entries)

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

 // _flags     [tos|0|F=0|M|A|I|f|0|vf|0000|00000|psize] (for method entries)

 // bit length [ 4 |1| 1 |1|1|1|1|1|1 |-4--|--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.

 // tos    = TosState

 // F      = the entry is for a field (or F=0 for a method)

 // A      = call site has an appendix argument (loaded from resolved references)

 // I      = interface call is forced virtual (must use a vtable index or vfinal)

 // f      = field or method is final

 // v      = field is volatile

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

 //

 // 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 Klass*)

 // _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      = Method* for non-virtual calls, unused by virtual calls.

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

 //            contains Klass* 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 Method*) 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 CallInfo;

 class ConstantPoolCacheEntry VALUE_OBJ_CLASS_SPEC {

   friend class VMStructs;

   friend class constantPoolCacheKlass;

   friend class ConstantPool;

   friend class InterpreterRuntime;

  private:

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

   volatile Metadata*   _f1;       // entry specific metadata field

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

   volatile intx     _flags;    // flags

   void set_bytecode_1(Bytecodes::Code code);

   void set_bytecode_2(Bytecodes::Code code);

   void set_f1(Metadata* f1) {

     Metadata* existing_f1 = (Metadata*)_f1; // read once

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

     _f1 = f1;

   }

   void release_set_f1(Metadata* f1);

   void set_f2(intx f2) {

     intx existing_f2 = _f2; // read once

     assert(existing_f2 == 0 || existing_f2 == f2, "illegal field change");

     _f2 = f2;

   }

   void set_f2_as_vfinal_method(Method* f2) {

     assert(is_vfinal(), "flags must be set");

     set_f2((intx)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_field_entry_shift       = 26,  // (F) is it a field or a method?

     has_method_type_shift      = 25,  // (M) does the call site have a MethodType?

     has_appendix_shift         = 24,  // (A) does the call site have an appendix argument?

     is_forced_virtual_shift    = 23,  // (I) is the interface reference forced to virtual mode?

     is_final_shift             = 22,  // (f) is the field or method final?

     is_volatile_shift          = 21,  // (v) is the field volatile?

     is_vfinal_shift            = 20,  // (vf) did the call resolve to a final method?

     // 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 {

     cp_index_bits              = 2*BitsPerByte,

     cp_index_mask              = right_n_bits(cp_index_bits),

     bytecode_1_shift           = cp_index_bits,

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

     bytecode_2_shift           = cp_index_bits + BitsPerByte,

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

   };

   // Initialization

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

   void initialize_resolved_reference_index(int ref_index) {

     assert(_f2 == 0, "set once");  // note: ref_index might be zero also

     _f2 = ref_index;

   }

   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

     Klass*          root_klass                   // needed by the GC to dirty the klass

   );

  private:

   void set_direct_or_vtable_call(

     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

   );

  public:

   void set_direct_call(                          // sets entry to exact concrete method entry

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

     methodHandle    method                       // the method to call

   );

   void set_vtable_call(                          // sets entry to vtable index

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

     methodHandle    method,                      // resolved method which declares the vtable index

     int             vtable_index                 // the vtable index

   );

   void set_itable_call(

     Bytecodes::Code invoke_code,                 // the bytecode used; must be invokeinterface

     methodHandle method,                         // the resolved interface method

     int itable_index                             // index into itable for the method

   );

   void set_method_handle(

     constantPoolHandle cpool,                    // holding constant pool (required for locking)

     const CallInfo &call_info                    // Call link information

   );

   void set_dynamic_call(

     constantPoolHandle cpool,                    // holding constant pool (required for locking)

     const CallInfo &call_info                    // Call link information

   );

   // 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 Method* 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(

     constantPoolHandle cpool,                    // holding constant pool (required for locking)

     Bytecodes::Code invoke_code,                 // _invokehandle or _invokedynamic

     const CallInfo &call_info                    // Call link information

   );

   // invokedynamic and invokehandle call sites have two entries in the

   // resolved references array:

   //   appendix   (at index+0)

   //   MethodType (at index+1)

   enum {

     _indy_resolved_references_appendix_offset    = 0,

     _indy_resolved_references_method_type_offset = 1,

     _indy_resolved_references_entries

   };

   Method*      method_if_resolved(constantPoolHandle cpool);

   oop        appendix_if_resolved(constantPoolHandle cpool);

   oop     method_type_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::_invokehandle    :    // fall through

       case Bytecodes::_invokedynamic   :    // fall through

       case Bytecodes::_invokeinterface : return 1;

       case Bytecodes::_putstatic       :    // fall through

       case Bytecodes::_putfield        :    // 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

   int indices() const                            { return _indices; }

   int indices_ord() const                        { return (intx)OrderAccess::load_ptr_acquire(&_indices); }

   int constant_pool_index() const                { return (indices() & cp_index_mask); }

   Bytecodes::Code bytecode_1() const             { return Bytecodes::cast((indices_ord() >> bytecode_1_shift) & bytecode_1_mask); }

   Bytecodes::Code bytecode_2() const             { return Bytecodes::cast((indices_ord() >> bytecode_2_shift) & bytecode_2_mask); }

   Metadata* f1_ord() const                       { return (Metadata *)OrderAccess::load_ptr_acquire(&_f1); }

   Method*   f1_as_method() const                 { Metadata* f1 = f1_ord(); assert(f1 == NULL || f1->is_method(), ""); return (Method*)f1; }

   Klass*    f1_as_klass() const                  { Metadata* f1 = f1_ord(); assert(f1 == NULL || f1->is_klass(), ""); return (Klass*)f1; }

   // Use the accessor f1() to acquire _f1's value. This is needed for

   // example in BytecodeInterpreter::run(), where is_f1_null() is

   // called to check if an invokedynamic call is resolved. This load

   // of _f1 must be ordered with the loads performed by

   // cache->main_entry_index().

   bool      is_f1_null() const                   { Metadata* f1 = f1_ord(); return f1 == NULL; }  // classifies a CPC entry as unbound

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

   Method*   f2_as_vfinal_method() const          { assert(is_vfinal(), ""); return (Method*)_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 is_forced_virtual() const                 { return (_flags & (1 << is_forced_virtual_shift)) != 0; }

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

   bool has_appendix() const                      { return (!is_f1_null()) && (_flags & (1 << has_appendix_shift))      != 0; }

   bool has_method_type() const                   { return (!is_f1_null()) && (_flags & (1 << has_method_type_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); }

 #if INCLUDE_JVMTI

   // 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(Method* old_method, Method* new_method,

          bool* trace_name_printed);

   bool check_no_old_or_obsolete_entries();

   Method* get_interesting_method_entry(Klass* k);

 #endif // INCLUDE_JVMTI

   // 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 ConstantPoolCache: public MetaspaceObj {

   friend class VMStructs;

   friend class MetadataFactory;

  private:

   int             _length;

   ConstantPool*   _constant_pool;          // the corresponding constant pool

   // Sizing

   debug_only(friend class ClassVerifier;)

   // Constructor

   ConstantPoolCache(int length,

                     const intStack& inverse_index_map,

                     const intStack& invokedynamic_inverse_index_map,

                     const intStack& invokedynamic_references_map) :

                           _length(length),

                           _constant_pool(NULL) {

     initialize(inverse_index_map, invokedynamic_inverse_index_map,

                invokedynamic_references_map);

     for (int i = 0; i < length; i++) {

       assert(entry_at(i)->is_f1_null(), "Failed to clear?");

     }

   }

   // Initialization

   void initialize(const intArray& inverse_index_map,

                   const intArray& invokedynamic_inverse_index_map,

                   const intArray& invokedynamic_references_map);

  public:

   static ConstantPoolCache* allocate(ClassLoaderData* loader_data,

                                      const intStack& cp_cache_map,

                                      const intStack& invokedynamic_cp_cache_map,

                                      const intStack& invokedynamic_references_map, TRAPS);

   bool is_constantPoolCache() const { return true; }

   int length() const                             { return _length; }

  private:

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

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

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

  public:

   int size() const                               { return size(length()); }

  private:

   // Helpers

   ConstantPool**        constant_pool_addr()   { return &_constant_pool; }

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

   friend class constantPoolCacheKlass;

   friend class ConstantPoolCacheEntry;

  public:

   // Accessors

   void set_constant_pool(ConstantPool* pool)   { _constant_pool = pool; }

   ConstantPool* constant_pool() const          { return _constant_pool; }

   // Fetches the entry at the given index.

   // 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;

   }

   // Code generation

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

   static ByteSize entry_offset(int raw_index) {

     int index = raw_index;

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

   }

 #if INCLUDE_JVMTI

   // 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(InstanceKlass* holder, bool* trace_name_printed);

   bool check_no_old_or_obsolete_entries();

   void dump_cache();

 #endif // INCLUDE_JVMTI

   // Deallocate - no fields to deallocate

   DEBUG_ONLY(bool on_stack() { return false; })

   void deallocate_contents(ClassLoaderData* data) {}

   bool is_klass() const { return false; }

   // Printing

   void print_on(outputStream* st) const;

   void print_value_on(outputStream* st) const;

   const char* internal_name() const { return "{constant pool cache}"; }

   // Verify

   void verify_on(outputStream* st);

 };

 #endif // SHARE_VM_OOPS_CPCACHEOOP_HPP