incubator-nuttx/include/sys/ipc.h

121 lines
4.1 KiB
C

/****************************************************************************
* include/sys/ipc.h
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
#ifndef __INCLUDE_SYS_IPC_H
#define __INCLUDE_SYS_IPC_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Mode bits: The lower order 9-bit bits are the standard mode bits */
#define IPC_MODE 0x01ff /* Mode bit mask */
#define IPC_CREAT 0x0200 /* Create key if key does not exist. */
#define IPC_EXCL 0x0400 /* Fail if key exists. */
#define IPC_NOWAIT 0x0800 /* Return error on wait. */
/* Keys: */
#define IPC_PRIVATE 0 /* Private key */
/* Control commands: */
#define IPC_RMID 0 /* Remove identifier */
#define IPC_SET 1 /* Set options */
#define IPC_STAT 2 /* Get options */
/****************************************************************************
* Public Type Definitions
****************************************************************************/
/****************************************************************************
* Public Data
****************************************************************************/
#undef EXTERN
#if defined(__cplusplus)
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/* The ipc_perm structure is used by three mechanisms for XSI interprocess
* communication (IPC): messages, semaphores, and shared memory. All use a
* common structure type, ipc_perm, to pass information used in determining
* permission to perform an IPC operation.
*/
struct ipc_perm
{
#if 0 /* User and group IDs not yet supported by NuttX */
uid_t uid; /* Owner's user ID */
gid_t gid; /* Owner's group ID */
uid_t cuid; /* Creator's user ID */
gid_t cgid; /* Creator's group ID */
#endif
mode_t mode; /* Read/write permission */
};
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
/****************************************************************************
* Name: ftok
*
* Description:
* Convert a pathname and a project identifier to a System V IPC key.
* The ftok() function uses the identity of the file named by the given
* pathname (which must refer to an existing, accessible file) and the
* least significant 8 bits of proj_id (which must be nonzero) to
* generate a key_t type System V IPC key, suitable for use with
* msgget(2), semget(2), or shmget(2).
*
* Input Parameters:
* pathname - identity of the file name
* proj_id - The value that uniquely project identifies.
*
* Returned Value:
* On success, the generated key_t value is returned.
* On failure -1 is returned, with errno indicating the error as for the
* stat(2) system call.
*
****************************************************************************/
key_t ftok(FAR const char *pathname, int proj_id);
#undef EXTERN
#if defined(__cplusplus)
}
#endif
#endif /* __INCLUDE_SYS_IPC_H */