--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/oops/cpCacheOop.hpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,325 @@
+/*
+ * Copyright 1998-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * 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,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+// 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  ]
+// _f1        [  entry specific   ]
+// _f2        [  entry specific   ]
+// _flags     [t|f|vf|v|m|h|unused|field_index] (for field entries)
+// bit length |4|1|1 |1|1|0|---7--|----16-----]
+// _flags     [t|f|vf|v|m|h|unused|eidx|psze] (for method entries)
+// bit length |4|1|1 |1|1|1|---7--|-8--|-8--]
+
+// --------------------------------
+//
+// with:
+// index  = original constant pool index
+// b1     = bytecode 1
+// b2     = bytecode 2
+// psze   = parameters size (method entries only)
+// eidx   = interpreter entry index (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)
+// vf     = virtual, 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: f flag  true if field is marked final
+// bit 26: vf flag true if virtual final method
+// bit 25: v flag true if field is volatile (only for fields)
+// bit 24: m flag true if invokeinterface used for method in class Object
+// bit 23: 0 for fields, 1 for methods
+//
+// 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
+// _f2      = field offset in words
+// _flags   = field type information, original field 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 all but virtual calls, unused by virtual calls
+//            (note: for interface calls, which are essentially virtual,
+//             contains klassOop for the corresponding interface.
+// _f2      = method/vtable index for virtual calls only, unused by all other
+//            calls.  The vf flag indicates this is a method pointer not an
+//            index.
+// _flags   = field type info (f section),
+//            virtual final entry (vf),
+//            interpreter entry index (eidx section),
+//            parameter size (psze 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;
+ 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 set_f2(intx f2)                           { assert(_f2 == 0    || _f2 == f2, "illegal field change"); _f2 = f2; }
+  int as_flags(TosState state, bool is_final, bool is_vfinal, bool is_volatile,
+               bool is_method_interface, bool is_method);
+  void set_flags(intx flags)                     { _flags = flags; }
+
+ public:
+  // specific bit values in flag field
+  // Note: the interpreter knows this layout!
+  enum FlagBitValues {
+    hotSwapBit    = 23,
+    methodInterface = 24,
+    volatileField = 25,
+    vfinalMethod  = 26,
+    finalField    = 27
+  };
+
+  enum { field_index_mask = 0xFFFF };
+
+  // start of type bits in flags
+  // Note: the interpreter knows this layout!
+  enum FlagValues {
+    tosBits      = 28
+  };
+
+  // Initialization
+  void set_initial_state(int index);             // sets entry to initial state
+
+  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_parameter_size(int value) {
+    assert(parameter_size() == 0 || parameter_size() == value,
+           "size must not change");
+    // Setting the parameter size by itself is only safe if the
+    // current value of _flags is 0, otherwise another thread may have
+    // updated it and we don't want to overwrite that value.  Don't
+    // bother trying to update it once it's nonzero but always make
+    // sure that the final parameter size agrees with what was passed.
+    if (_flags == 0) {
+      Atomic::cmpxchg_ptr((value & 0xFF), &_flags, 0);
+    }
+    guarantee(parameter_size() == value, "size must not change");
+  }
+
+  // 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::_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 constant_pool_index() const                { return _indices & 0xFFFF; }
+  Bytecodes::Code bytecode_1() const             { return Bytecodes::cast((_indices >> 16) & 0xFF); }
+  Bytecodes::Code bytecode_2() const             { return Bytecodes::cast((_indices >> 24) & 0xFF); }
+  volatile oop  f1() const                       { return _f1; }
+  intx f2() const                                { return _f2; }
+  int  field_index() const;
+  int  parameter_size() const                    { return _flags & 0xFF; }
+  bool is_vfinal() const                         { return ((_flags & (1 << vfinalMethod)) == (1 << vfinalMethod)); }
+  bool is_volatile() const                       { return ((_flags & (1 << volatileField)) == (1 << volatileField)); }
+  bool is_methodInterface() const                { return ((_flags & (1 << methodInterface)) == (1 << methodInterface)); }
+  bool is_byte() const                           { return (((uintx) _flags >> tosBits) == btos); }
+  bool is_char() const                           { return (((uintx) _flags >> tosBits) == ctos); }
+  bool is_short() const                          { return (((uintx) _flags >> tosBits) == stos); }
+  bool is_int() const                            { return (((uintx) _flags >> tosBits) == itos); }
+  bool is_long() const                           { return (((uintx) _flags >> tosBits) == ltos); }
+  bool is_float() const                          { return (((uintx) _flags >> tosBits) == ftos); }
+  bool is_double() const                         { return (((uintx) _flags >> tosBits) == dtos); }
+  bool is_object() const                         { return (((uintx) _flags >> tosBits) == atos); }
+  TosState flag_state() const                    { assert( ( (_flags >> tosBits) & 0x0F ) < number_of_states, "Invalid state in as_flags");
+                                                   return (TosState)((_flags >> tosBits) & 0x0F); }
+
+  // Code generation support
+  static WordSize size()                         { return in_WordSize(sizeof(ConstantPoolCacheEntry) / HeapWordSize); }
+  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();
+  void update_pointers(HeapWord* beg_addr, HeapWord* end_addr);
+
+  // 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);
+  bool is_field_entry() const                    { return (_flags & (1 << hotSwapBit)) == 0; }
+  bool is_method_entry() const                   { return (_flags & (1 << hotSwapBit)) != 0; }
+
+  // Debugging & Printing
+  void print (outputStream* st, int index) const;
+  void verify(outputStream* st) const;
+
+  static void verify_tosBits() {
+    assert(tosBits == 28, "interpreter now assumes tosBits is 28");
+  }
+};
+
+
+// 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 arrayOopDesc {
+  friend class VMStructs;
+ private:
+  constantPoolOop _constant_pool;                // the corresponding constant pool
+
+  // Sizing
+  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;
+
+ public:
+  // Initialization
+  void initialize(intArray& inverse_index_map);
+
+  // Accessors
+  void set_constant_pool(constantPoolOop pool)   { oop_store_without_check((oop*)&_constant_pool, (oop)pool); }
+  constantPoolOop constant_pool() const          { return _constant_pool; }
+  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(constantPoolCacheOopDesc)); }
+
+  // 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);
+};