proxyOop.hpp

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/* Copyright 1994, 1995 LongView Technologies L.L.C. $Revision: 1.8 $ */
/* Copyright (c) 2006, Sun Microsystems, Inc.
All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the 
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    * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
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          disclaimer in the documentation and/or other materials provided with the distribution.
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// proxy objects are handles to external data.

// memory layout:
//    [header      ]
//    [klass_field ]
//    [pointer     ]

const pointer_no     = sizeof(memOopDesc)/oopSize;
const pointer_offset = sizeof(memOopDesc) - Mem_Tag;

class proxyOopDesc: public memOopDesc {
 private:
  void* _pointer;
 protected:
  proxyOopDesc* addr() const { return (proxyOopDesc*)memOopDesc::addr(); }

 public:
  friend proxyOop as_proxyOop(void* p) { return proxyOop(as_memOop(p)); }

  // sizing
  static int header_size() { return sizeof(proxyOopDesc)/oopSize; }

  void* get_pointer() const    { return addr()->_pointer; }
  void  set_pointer(void *ptr) { addr()->_pointer = ptr;  }

  void  null_pointer() { set_pointer(NULL); }

  bool is_null() const    { return get_pointer() ==       NULL; }
  bool is_allOnes() const { return get_pointer() == (void*) -1; }

  smi foreign_hash() const { return smi(get_pointer()) >> Tag_Size; }

  bool same_pointer_as(proxyOop x) const {
    return get_pointer() == x->get_pointer();
  }

  void bootstrap_object(bootstrap* st);

 private:
   unsigned char* addr_at(int offset) const {
     return ((unsigned char*) get_pointer()) + offset;
   }
 public:
  unsigned char byte_at(int offset) const {
    return *addr_at(offset);
  }
  void byte_at_put(int offset, unsigned char c) {
    *addr_at(offset) = c;
  }
  doubleByte doubleByte_at(int offset) const { 
    return *((doubleByte*) addr_at(offset));
  }
  void doubleByte_at_put(int offset, doubleByte db) {
     *((doubleByte*) addr_at(offset)) = db;
  }
  long long_at(int offset) const {
    return *((long*) addr_at(offset));
  }
  void long_at_put(int offset, long l) {
    *((long*) addr_at(offset)) = l;
  }

  float float_at(int offset) const {
    return *((float*) addr_at(offset));
  }
  void float_at_put(int offset, float f) {
    *((float*) addr_at(offset)) = f;
  }

  double double_at(int offset) const {
    return *((double*) addr_at(offset));
  }
  void double_at_put(int offset, double d) {
    *((double*) addr_at(offset)) = d;
  }

  friend proxyKlass;
};

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