/* SPDX-License-Identifier: BSD-2-Clause */
/**
* @file
*
* @brief Internal Support for POSIX Shared Memory
*/
/*
* Copyright (c) 2016 Gedare Bloom.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _RTEMS_POSIX_SHM_H
#define _RTEMS_POSIX_SHM_H
#include <rtems/score/objectdata.h>
#include <rtems/score/threadq.h>
#include <sys/types.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* @defgroup POSIXShmPrivate POSIX Shared Memory Private Support
*
* @ingroup POSIXAPI
*
* Internal implementation support for POSIX shared memory.
* @{
*/
typedef struct POSIX_Shm_Object_operations POSIX_Shm_Object_operations;
extern const POSIX_Shm_Object_operations _POSIX_Shm_Object_operations;
/**
* @brief Encapsulation for the storage and manipulation of shm objects.
*/
typedef struct {
/**
* @brief The handle is private for finding object storage.
*/
void *handle;
/**
* @brief The number of bytes allocated to the object. A size of 0 with
* a handle of NULL means no object is allocated.
*/
size_t size;
/**
* @brief Implementation-specific operations on shm objects.
*/
const POSIX_Shm_Object_operations *ops;
} POSIX_Shm_Object;
/**
* @brief Operations on POSIX Shared Memory Objects.
*/
struct POSIX_Shm_Object_operations {
/**
* @brief Allocates a new @a shm_obj with initial @a size.
*
* New shared memory is initialized to zeroes.
*
* Returns 0 for success.
*/
int ( *object_create ) ( POSIX_Shm_Object *shm_obj, size_t size );
/**
* @brief Changes the @a shm_obj size to @a size.
*
* Zeroes out the portion of the shared memory object that shrinks or grows.
*
* Returns 0 for success.
*/
int ( *object_resize ) ( POSIX_Shm_Object *shm_obj, size_t size );
/**
* @brief Deletes the @a shm_obj.
*
* Zeroes out the memory.
*
* Returns 0 for success.
*/
int ( *object_delete ) ( POSIX_Shm_Object *shm_obj );
/**
* @brief Copies up to @count bytes of the @a shm_obj data into @a buf.
*
* Returns the number of bytes read (copied) into @a buf.
*/
int ( *object_read ) ( POSIX_Shm_Object *shm_obj, void *buf, size_t count );
/**
* @brief Maps a shared memory object.
*
* Establishes a memory mapping between the shared memory object and the
* caller.
*
* Returns the mapped address of the object.
*/
void * ( *object_mmap ) ( POSIX_Shm_Object *shm_obj, size_t len, int prot, off_t off);
};
/**
* @brief Control for a POSIX Shared Memory Object
*/
typedef struct {
Objects_Control Object;
Thread_queue_Control Wait_queue;
int reference_count;
POSIX_Shm_Object shm_object;
uid_t uid;
gid_t gid;
mode_t mode;
int oflag;
time_t atime;
time_t mtime;
time_t ctime;
} POSIX_Shm_Control;
/**
* @brief The POSIX Shared Memory objects information.
*/
extern Objects_Information _POSIX_Shm_Information;
/**
* @brief Macro to define the objects information for the POSIX Shared Memory
* objects.
*
* This macro should only be used by <rtems/confdefs.h>.
*
* @param max The configured object maximum (the OBJECTS_UNLIMITED_OBJECTS flag
* may be set).
*/
#define POSIX_SHM_INFORMATION_DEFINE( max ) \
OBJECTS_INFORMATION_DEFINE( \
_POSIX_Shm, \
OBJECTS_POSIX_API, \
OBJECTS_POSIX_SHMS, \
POSIX_Shm_Control, \
max, \
_POSIX_PATH_MAX, \
NULL \
)
/**
* @brief object_create operation for shm objects stored in RTEMS Workspace.
*/
extern int _POSIX_Shm_Object_create_from_workspace(
POSIX_Shm_Object *shm_obj,
size_t size
);
/**
* @brief object_delete operation for shm objects stored in RTEMS Workspace.
*/
extern int _POSIX_Shm_Object_delete_from_workspace( POSIX_Shm_Object *shm_obj );
/**
* @brief object_resize operation for shm objects stored in RTEMS Workspace.
*/
extern int _POSIX_Shm_Object_resize_from_workspace(
POSIX_Shm_Object *shm_obj,
size_t size
);
/**
* @brief object_read operation for shm objects stored in RTEMS Workspace.
*/
extern int _POSIX_Shm_Object_read_from_workspace(
POSIX_Shm_Object *shm_obj,
void *buf,
size_t count
);
/**
* @brief object_mmap operation for shm objects stored in RTEMS Workspace.
*/
extern void * _POSIX_Shm_Object_mmap_from_workspace(
POSIX_Shm_Object *shm_obj,
size_t len,
int prot,
off_t off
);
/**
* @brief object_create operation for shm objects stored in C program heap.
*/
extern int _POSIX_Shm_Object_create_from_heap(
POSIX_Shm_Object *shm_obj,
size_t size
);
/**
* @brief object_delete operation for shm objects stored in C program heap.
*/
extern int _POSIX_Shm_Object_delete_from_heap( POSIX_Shm_Object *shm_obj );
/**
* @brief object_resize operation for shm objects stored in C program heap.
*/
extern int _POSIX_Shm_Object_resize_from_heap(
POSIX_Shm_Object *shm_obj,
size_t size
);
/**
* @brief object_read operation for shm objects stored in C program heap.
*/
extern int _POSIX_Shm_Object_read_from_heap(
POSIX_Shm_Object *shm_obj,
void *buf,
size_t count
);
/**
* @brief object_mmap operation for shm objects stored in C program heap.
*/
extern void * _POSIX_Shm_Object_mmap_from_heap(
POSIX_Shm_Object *shm_obj,
size_t len,
int prot,
off_t off
);
/** @} */
#ifdef __cplusplus
}
#endif
#endif
