shared_memory.h

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#ifndef SHARED_MEMORY_CLASS
#define SHARED_MEMORY_CLASS

#ifndef EMBEDDED_BUILD

/*****************************************************************************\
*                                                                             *
*  Name   : shared_memory                                                     *
*  Author : Chris Koeritz                                                     *
*                                                                             *
*******************************************************************************
* Copyright (c) 2002-$now By Author.  This program is free software; you can  *
* redistribute it and/or modify it under the terms of the GNU General Public  *
* License as published by the Free Software Foundation; either version 2 of   *
* the License or (at your option) any later version.  This is online at:      *
*     http://www.fsf.org/copyleft/gpl.html                                    *
* Please send any updates to: fred@gruntose.com                               *
\*****************************************************************************/

#include <basis/object_base.h>

// forward.
class byte_filer;
class rendezvous;


class OPSYSTEM_CLASS_STYLE shared_memory : public virtual object_base
{
public:
  shared_memory(int size, const char *identity);

  virtual ~shared_memory();

  IMPLEMENT_CLASS_NAME("shared_memory");

  bool valid() const { return _valid; }

  int size() const { return _size; }

  const istring &identity() const;

  bool first_usage(byte *locked_memory, int max_compare);

  byte *lock();

  void unlock(byte * &to_unlock);

  static istring unique_shared_mem_identifier(int sequencer);

private:
  rendezvous *_locking;  
#ifdef __UNIX__
  int _the_memory;  
#elif defined(__WIN32__)
  void *_the_memory;  
#endif
  bool _valid;  
  istring *_identity;  
  int _size;  

  // these do the actual work of getting the memory.
  byte *locked_grab_memory();
  void locked_release_memory(byte * &to_unlock);

  static istring special_filename(const istring &identity);

  // forbidden.
  shared_memory(const shared_memory &);
  shared_memory &operator =(const shared_memory &);
};

#endif // embedded.

#endif  // outer guard.

---