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Diffstat (limited to 'cpukit/include/rtems/posix/shm.h')
| -rw-r--r-- | cpukit/include/rtems/posix/shm.h | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/cpukit/include/rtems/posix/shm.h b/cpukit/include/rtems/posix/shm.h new file mode 100644 index 0000000000..d2b6036493 --- /dev/null +++ b/cpukit/include/rtems/posix/shm.h @@ -0,0 +1,213 @@ +/** + * @file + * + * @brief Internal Support for POSIX Shared Memory + */ + +/* + * Copyright (c) 2016 Gedare Bloom. + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.org/license/LICENSE. + */ + +#ifndef _RTEMS_POSIX_SHM_H +#define _RTEMS_POSIX_SHM_H + +#include <rtems/score/object.h> +#include <rtems/score/threadq.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 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 |