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/**
* @file
*/
/*
* 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <errno.h>
#include <string.h>
#include <rtems/score/wkspace.h>
#include <rtems/posix/shmimpl.h>
int _POSIX_Shm_Object_create_from_workspace(
POSIX_Shm_Object *shm_obj,
size_t size
)
{
shm_obj->handle = _Workspace_Allocate( size );
if ( shm_obj->handle == NULL ) {
return ENOMEM;
}
memset( shm_obj->handle, 0, size );
shm_obj->size = size;
return 0;
}
int _POSIX_Shm_Object_delete_from_workspace( POSIX_Shm_Object *shm_obj )
{
/* zero out memory before releasing it. */
memset( shm_obj->handle, 0, shm_obj->size );
_Workspace_Free( shm_obj->handle );
shm_obj->handle = NULL;
shm_obj->size = 0;
return 0;
}
int _POSIX_Shm_Object_resize_from_workspace(
POSIX_Shm_Object *shm_obj,
size_t size
)
{
int err;
if ( size == 0 ) {
err = _POSIX_Shm_Object_delete_from_workspace( shm_obj );
} else if ( shm_obj->handle == NULL && shm_obj->size == 0 ) {
err = _POSIX_Shm_Object_create_from_workspace( shm_obj, size );
} else {
/* Refuse to resize a workspace object. */
err = EIO;
}
return err;
}
int _POSIX_Shm_Object_read_from_workspace(
POSIX_Shm_Object *shm_obj,
void *buf,
size_t count
)
{
if ( shm_obj == NULL || shm_obj->handle == NULL )
return 0;
if ( shm_obj->size < count ) {
count = shm_obj->size;
}
memcpy( buf, shm_obj->handle, count );
return count;
}
void * _POSIX_Shm_Object_mmap_from_workspace(
POSIX_Shm_Object *shm_obj,
size_t len,
int prot,
off_t off
)
{
if ( shm_obj == NULL || shm_obj->handle == NULL )
return 0;
/* This is already checked by mmap. Maybe make it a debug assert? */
if ( shm_obj->size < len + off ) {
return NULL;
}
return (char*)shm_obj->handle + off;
}
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