150 lines
6.2 KiB
C
Executable File
150 lines
6.2 KiB
C
Executable File
/****************************************************************************
|
|
* mm/shm/shmget.c
|
|
*
|
|
* Copyright (C) 2014 Gregory Nutt. All rights reserved.
|
|
* Author: Gregory Nutt <gnutt@nuttx.org>
|
|
*
|
|
* 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.
|
|
* 3. Neither the name NuttX nor the names of its contributors may be
|
|
* used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* 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.
|
|
*
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <nuttx/config.h>
|
|
|
|
#include <sys/shm.h>
|
|
#include <sys/ipc.h>
|
|
#include <errno.h>
|
|
|
|
#ifdef CONFIG_MM_SHM
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Private Types
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Private Data
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Private Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: shmget
|
|
*
|
|
* Description:
|
|
* The shmget() function will return the shared memory identifier
|
|
* associated with key.
|
|
*
|
|
* A shared memory identifier, associated data structure, and shared
|
|
* memory segment of at least size bytes is created for key if one of the
|
|
* following is true:
|
|
*
|
|
* - The argument key is equal to IPC_PRIVATE.
|
|
* - The argument key does not already have a shared memory identifier
|
|
* associated with it and (shmflg & IPC_CREAT) is non-zero.
|
|
*
|
|
* Upon creation, the data structure associated with the new shared memory
|
|
* identifier will be initialized as follows:
|
|
*
|
|
* - The values of shm_perm.cuid, shm_perm.uid, shm_perm.cgid, and
|
|
* shm_perm.gid are set equal to the effective user ID and effective
|
|
* group ID, respectively, of the calling process.
|
|
* - The low-order nine bits of shm_perm.mode are set equal to the low-
|
|
* order nine bits of shmflg.
|
|
* - The value of shm_segsz is set equal to the value of size.
|
|
* - The values of shm_lpid, shm_nattch, shm_atime, and shm_dtime are
|
|
* set equal to 0.
|
|
* - The value of shm_ctime is set equal to the current time.
|
|
*
|
|
* When the shared memory segment is created, it will be initialized with
|
|
* all zero values.
|
|
*
|
|
* Input Parameters:
|
|
* key - The key that is used to access the unique shared memory
|
|
* identifier.
|
|
* size - The shared memory region that is created will be at least
|
|
* this size in bytes.
|
|
* shmflgs - See IPC_* definitions in sys/ipc.h. Only the values
|
|
* IPC_PRIVATE or IPC_CREAT are supported.
|
|
*
|
|
* Returned Value:
|
|
* Upon successful completion, shmget() will return a non-negative
|
|
* integer, namely a shared memory identifier; otherwise, it will return
|
|
* -1 and set errno to indicate the error.
|
|
*
|
|
* - EACCES
|
|
* A shared memory identifier exists for key but operation permission
|
|
* as specified by the low-order nine bits of shmflg would not be
|
|
* granted.
|
|
* - EEXIST
|
|
* A shared memory identifier exists for the argument key but
|
|
* (shmflg & IPC_CREAT) && (shmflg & IPC_EXCL) are non-zero.
|
|
* - EINVAL
|
|
* A shared memory segment is to be created and the value of size is
|
|
* less than the system-imposed minimum or greater than the system-
|
|
* imposed maximum.
|
|
* - EINVAL
|
|
* No shared memory segment is to be created and a shared memory
|
|
* segment exists for key but the size of the segment associated with
|
|
* it is less than size and size is not 0.
|
|
* - ENOENT
|
|
* A shared memory identifier does not exist for the argument key and
|
|
* (shmflg & IPC_CREAT) is 0.
|
|
* - ENOMEM
|
|
* A shared memory identifier and associated shared memory segment
|
|
* will be created, but the amount of available physical memory is
|
|
* not sufficient to fill the request.
|
|
* - ENOSPC
|
|
* A shared memory identifier is to be created, but the system-imposed
|
|
* limit on the maximum number of allowed shared memory identifiers
|
|
* system-wide would be exceeded.
|
|
*
|
|
****************************************************************************/
|
|
|
|
int shmget(key_t key, size_t size, int shmflg)
|
|
{
|
|
#warning Not implemented
|
|
set_errno(ENOSYS);
|
|
return ERROR;
|
|
}
|
|
|
|
#endif /* CONFIG_MM_SHM */
|
|
|