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/* SysV shared memory for Hurd.
Copyright (C) 2005-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <stddef.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <dirent.h>
#include <sys/stat.h>
#include <sys/shm.h>
/* Description of an shm attachment. */
struct sysvshm_attach
{
/* Linked list. */
struct sysvshm_attach *next;
/* Map address. */
void *addr;
/* Map size. */
size_t size;
};
/* List of attachments. */
static struct sysvshm_attach *sysvshm_list;
/* A lock to protect the linked list of shared memory attachments. */
static struct mutex sysvshm_lock = MUTEX_INITIALIZER;
/* Adds a segment attachment. */
error_t
__sysvshm_add (void *addr, size_t size)
{
struct sysvshm_attach *shm;
shm = malloc (sizeof (*shm));
if (shm == NULL)
return errno;
__mutex_lock (&sysvshm_lock);
shm->addr = addr;
shm->size = size;
shm->next = sysvshm_list;
sysvshm_list = shm;
__mutex_unlock (&sysvshm_lock);
return 0;
}
/* Removes a segment attachment. On success, returns 0 and sets *SIZE to its
size. Returns EINVAL if not found. */
error_t
__sysvshm_remove (void *addr, size_t *size)
{
struct sysvshm_attach *shm;
struct sysvshm_attach **pshm = &sysvshm_list;
__mutex_lock (&sysvshm_lock);
shm = sysvshm_list;
while (shm != NULL)
{
shm = *pshm;
if (shm->addr == addr)
{
*pshm = shm->next;
*size = shm->size;
__mutex_unlock (&sysvshm_lock);
free (shm);
return 0;
}
pshm = &shm->next;
shm = shm->next;
}
__mutex_unlock (&sysvshm_lock);
return EINVAL;
}
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