diff options
Diffstat (limited to 'hurd/sysvshm.c')
-rw-r--r-- | hurd/sysvshm.c | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/hurd/sysvshm.c b/hurd/sysvshm.c new file mode 100644 index 0000000000..5d538a6373 --- /dev/null +++ b/hurd/sysvshm.c @@ -0,0 +1,97 @@ +/* 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; +} |