* Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.

#ifndef SHARE_VM_UTILITIES_DECODER_HPP

#define SHARE_VM_UTILITIES_DECODER_HPP

#include "runtime/mutex.hpp"

class NullDecoder: public CHeapObj {

public:

         not_available = -10,  // real decoder is not available

         no_error = 0,         // successfully decoded frames

         helper_init_error     // SymInitialize failed (Windows only)

  NullDecoder() {

    _decoder_status = not_available;

  }

  ~NullDecoder() {};

  virtual bool decode(address pc, char* buf, int buflen, int* offset,

    const char* modulepath = NULL) {

    return false;

  }

  virtual bool demangle(const char* symbol, char* buf, int buflen) {

    return false;

  }

  virtual bool can_decode_C_frame_in_vm() const {

    return false;

  }

  virtual decoder_status status() const {

    return _decoder_status;

  }

  virtual bool has_error() const {

    return is_error(_decoder_status);

  }

  static bool is_error(decoder_status status) {

    return (status > 0);

  }

protected:

  decoder_status  _decoder_status;

};

class Decoder: AllStatic {

public:

  static bool decode(address pc, char* buf, int buflen, int* offset, const char* modulepath = NULL);

  static bool demangle(const char* symbol, char* buf, int buflen);

  static void shutdown();

protected:

  static NullDecoder* get_decoder();

private:

  static NullDecoder*     _decoder;

  static NullDecoder      _do_nothing_decoder;

protected:

  static Mutex*       _decoder_lock;

#endif // SHARE_VM_UTILITIES_DECODER_HPP