/*
************************************************************************
**
**	Copyright (c) 2010 by
**		Core|Vision B.V.
**		Cereslaan 10b
**		5384 VT  Heesch
**		The Netherlands
**
**	All Rights Reserved
**
************************************************************************
*/
/*
************************************************************************
**
**	Project name:   Dual Inventive: Utility Library
**	Filename:       cp3000-shmem.h
**	Author:			Jack Weeland
**	Date:			October 26, 2010
**	File version:	1.00	of October 26, 2010
**
************************************************************************
*/
/*
************************************************************************
**
**	CP3000 inter-process shared memory functions
**
************************************************************************
*/

#ifndef	__CP3000_SHARED_MEMORY_H
#define	__CP3000_SHARED_MEMORY_H

/*
**	Datatype
*/

typedef struct CP3000_SHARED_MEMORY *cp3000_shmem_t;

/*
**	Constants for the 'flags' to 'cp3000_shmem_init()'
*/

#define	CP3000_SHMEM_READ		0x0001	// read only access
#define	CP3000_SHMEM_WRITE		0x0002	// read and write access
#define	CP3000_SHMEM_PRIVATE	0x0100	// access for the current user only

/*
**	Exported functions
*/

// Initialization and destruction
cp3000_shmem_t cp3000_shmem_init(const char *name, size_t size, unsigned int flags);
int cp3000_shmem_deinit(cp3000_shmem_t);

// Provide access to the shared memory region
void *cp3000_shmem(cp3000_shmem_t);
// Get the size of the shared memory object (may be changed after 'cp3000_shmem_init()')
size_t cp3000_shmem_size(cp3000_shmem_t);

// Safe access, with size checking etc.
// Return the number of bytes copied
int cp3000_shmem_read(cp3000_shmem_t, void *buffer, size_t bufsz);
int cp3000_shmem_read_at(cp3000_shmem_t, int offset, void *buffer, size_t bufsz);
int cp3000_shmem_write(cp3000_shmem_t, const void *buffer, size_t bufsz);
int cp3000_shmem_write_at(cp3000_shmem_t, int offset, const void *buffer, size_t bufsz);

#endif	/* __CP3000_SHARED_MEMORY_H */