The Allocator class is just a thin wrapper around ACE_Malloc<> that moves some of the details out of the application logic.
// $Id: page04.html,v 1.6 1999/04/03 21:58:06 jcej Exp $
#ifndef MPOOL_H
#define MPOOL_H
// Everything else we need is in this one header
#include "ace/Malloc.h"
#if !defined (ACE_LACKS_SYSV_SHMEM)
/*
  With this we will abstract away some of the details of the memory
  pool.  Note that we don't treat this as a singleton because an
  application may need more than one pool.  Each would have a
  different name and be used for different purposes.
 */
class Allocator
{
public:
  // The pool name will be used to create a unique semaphore to
  // keep this pool separate from others.
  Allocator (const char * _name = "MemoryPool");
  ~Allocator (void);
  typedef ACE_Malloc<ACE_MMAP_MEMORY_POOL, ACE_SV_Semaphore_Simple> pool_t;
  // Provide an accessor to the pool.  This will also allocate the
  // pool when first invoked.
  pool_t &pool (void);
protected:
  // The name we gave to the pool
  char *name_;
    
  pool_t *pool_;
};
/*
  The client and server need to agree on a certain set of values.  By
  placing them in the Constants class we can eliminate a bit of confusion.
 */
class Constants
{
public:
  // The semaphore keys are needed for the two semaphores that
  // synch access to the shared memory area.
  static const int SEM_KEY_1;
  static const int SEM_KEY_2;
  // How big the pool will be and what we'll put into it.  A real
  // app wouldn't need SHMDATA of course.
  static const int SHMSZ;
  static const char *SHMDATA;
  // The name assigned to the memory pool by the server is needed
  // by the client.  Without it, the pool cannot be found.
  // Likewise, the name the server will bind() to the region of the 
  // pool must be available to the client.
  static const char *PoolName;
  static const char *RegionName;
};
#endif /* ACE_LACKS_SYSV_SHMEM */
#endif /* MPOOL_H */
* Actually, some implementations may require a different number of parameters. That's why ACE uses those funky macros. ACE_MMAP_MEMORY_POOL for instance turns into ACE_MMAP_Memory_Pool on Linux but may do other things on your platform.